WO2002031465A1

WO2002031465A1 - Collection of particles to be analysed by assay systems

Info

Publication number: WO2002031465A1
Application number: PCT/AU2001/001287
Authority: WO
Inventors: Tim O'meara; Euan Roger Tovey
Original assignee: Inhalix Pty Ltd
Priority date: 2000-10-13
Filing date: 2001-10-12
Publication date: 2002-04-18

Abstract

A device and method for sampling particulate matter present on an object. The device includes an adhesive member and a macromolecular species binding member wherein the adhesive member includes a face for contacting an object and for binding said particulate matter present on the object and wherein further, the macromolecular species binding member is adapted to overlay at least a portion of the face of the adhesive member following sampling.

Description

"Collection of particles to be analysed by assay systems"

Field of the Invention

The present invention relates to a method and a device for sampling particles containing specific macromolecules to which people may have a pathogenic reaction. Background Art

Many individuals suffer from allergic diseases such as asthma, rhinitis and eczema. A feature of these diseases is that most affected individuals have developed abnormally high levels of specific immunoglobulin class E (IgE). The IgE binds to particular macromolecules found in the environment of the individual, initiating a sequence of bio-molecular events which may result in allergic symptoms. These environmental macromolecules, termed allergens, are usually proteins. The usual route of exposure to such allergens is the inhalation of airborne particles carrying the allergens, although other routes (injection in the case of insect venom, skin contact, or ingestion in the case of some foods) are also recognised. Commonly identified aeroallergens are produced by house dust mites, cockroaches, rye grass pollen and cats, although there are many other sources. Tests are available which measure the level and specificity of the IgE to provide clinical diagnostic information about the allergies of a particular individual.

For individuals with specific allergies there is a need to measure the quantity of the allergens in their environment. In this way such people can take action to reduce their exposure and improve their symptoms. Furthermore, information about allergen levels can form an important component of the management of the disease and in other cases it may be used to reduce the risk of the disease occurring. Information about the level of exposure can be used to establish exposure thresholds associated with clinical outcomes. Such thresholds may then be used to determine the level of risk for an individual or a community.

There are many methods of determining the level of allergen exposure. For indoor allergens it is common to obtain samples of dust from various indoor surfaces and to measure the level of allergen in the sampled dust. Typically, the dust may be collected from beds, floors, clothing and other sites where it accumulates and subjected to sieving and extraction of proteins. Subsequently, the quantity of specific allergens among these proteins may be determined by immunoassay.

As mentioned above, personal exposure to such allergens generally occurs by inhaling airborne particles carrying the allergens. The allergen level in the dust collected from different sites is considered an index of the amount of airborne allergen, although a precise correlation is not found. In this regard, many variables may influence the dynamic relationship between the amount of aeroallergen inhaled and the allergen concentration in the dust at different sites including the degree of physical disturbance of the site, the proximity of the person to the site, interactive forces such as electrostatic charge which may influence the liberation and attraction of such particles to surfaces, and the effects of ventilation of the airspace. Measurement of the allergen level in dust at various sites is therefore useful to determine the effectiveness of treatment of a site to reduce allergen exposure. For some purposes, a more meaningful index of human exposure to allergen is the measured amount of airborne allergen over a short or a long time frame. In this case, the airborne allergen may be collected by filtering known volumes of air or by impacting airborne particles in that volume of air onto a sticky surface or into a liquid from which the allergens are later collected and analysed.

The amount of allergen previously airborne may also be measured. This is possible by measuring the amount of allergen which has settled out onto a clean surface over a period of time, for example, onto a Petri dish over a week. Such a method was described by Tovey et al, in Clinical Experimental Allergy, Vol 22, pages 67-74. The method involved the extraction of a mite allergen from collected dust. The amount of allergen was then measured by double antibody ELISA immunoassay.

One difficulty with this, and many other methods which use aeroallergen, is that the quantity of allergen collected from the air or onto a Petri dish over a week is in the order of only a few nanograms, even in areas with high exposure levels. This amount is near the lower limit of sensitivity of conventional ELISA immunoassay methods.

ELISA sandwich assays use one specific monoclonal antibody bound to a plastic well to capture a solubilised allergen from solution. A second antibody, also specific for the allergen, but to a different part of the allergen, is then used to form a sandwich, with the allergen in the middle. The second antibody carries a label which can be used to generate a measurable signal. When appropriately designed, the level of the signal generated in this assay is proportional to the amount of allergen.

A method of directly measuring the allergens associated with individual particles is described in US Patent No 5955376 and International Patent Application No PCT /AU99/00017. This method involves permanently retaining the particles carrying allergens on a protein binding matrix. When the matrix is wet, the allergens may be extracted from individual particles and bound to the protein binding matrix in close proximity to each particle. Subsequent immunostaining of the allergens enables identification of the individual particles from which the allergens originated. The process of extraction of the allergens, and their subsequent immunostaining follows conventional immunohistochemistry techniques. Following staining, measurements can be made on both the particle and the immunostained allergen using instruments suitable for this purpose such as microscopes and high resolution image scanners. This method is extremely sensitive as it enables the detection of a single dust particle carrying an allergen.

For both public and research applications, however, devices/methods of analysis of environmental allergens which are sufficiently simple to allow use by unskilled individuals are required. Such devices/methods would enable the unskilled user to monitor their home environment to determine exposure.

Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of this application. Disclosure of the Invention

In a first aspect, the present invention provides a device for sampling particulate matter present on an object, the device including an adhesive member and a macromolecular species binding member wherein the adhesive member includes a face for contacting an object and for binding said particulate matter present on the object and wherein further, the macromolecular species binding member is adapted to overlay at least a portion of the face of the adhesive member following sampling.

In one embodiment, the adhesive member is an adhesive tape having an adhesive surface and a back surface and wherein the face of the adhesive member is the adhesive surface of the tape. In this embodiment, the adhesive tape is selected for compatibility with the subsequent assay system and may include, but is not limited to the three adhesive tapes described in Razmovski V, O'Meara TJ, Taylor DJM, Tovey ER, "A new method for simultaneous immunodetection and morphologic identification of individual sources of pollen allergens" /. Allergjr and Clin Immunol. (2000) 105: No. 4, 725-31. Preferably, the macromolecular species binding member is a protein binding membrane. In this embodiment, the protein binding membrane is selected for compatibility with a subsequent assay system and may include, but is not limited to, nitrocellulose, PVDF and nylons. Typically, both the adhesive member and the macromolecular species binding member are mounted on a support member. The support member is preferably made from a material such as paper, cardboard or plastic although other materials are readily envisaged. Furthermore, the material used may range from a rigid material such as 'hard' plastic to a soft material such as 'spongy¹ closed cell foam.

Preferably, the adhesive member and the macromolecular species binding member are hingedly connected such that each member may be moved between a first closed position relative to each other to a second open position relative to each other. In the second open position, the face of the adhesive member may be brought into contact with the object to be sampled. In this embodiment, preferably the support member is hinged such that it forms a book-like structure. In this way, the support member may be opened and closed thereby allowing the adhesive member and the macromolecular species binding member to move relative to each other. Typically, the device includes a protective member for covering the face of the adhesive member prior to the sampling of particulate matter. The protective member may also cover the adhesive member after sampling of particulate matter and before overlay with the macromolecular species binding member. The protective member may include a film which, to facilitate removal prior to sampling, includes a pull tab. Other means of protecting the adhesive member are readily envisaged. It is also preferred that the macromolecular species binding member is protected by a film or other like means before and during sampling of an object. After sampling has been performed, the film may be removed to facilitate the overlay of the face of the adhesive member with the macromolecular species binding member.

In another embodiment, the adhesive member is mounted on a cylindrical member. In this embodiment, it is envisaged that the adhesive member is an adhesive tape which is removably mounted on the cylindrical member. The benefit of such a design is that the cylindrical member may be rolled across an object thereby enabling a surface larger than the area of the adhesive member to be sampled. In this embodiment, the adhesive member and the macromolecular species binding member are not hingedly connected but rather are separate components of the device. Accordingly, the tape may be removed from the cylindrical member and subsequently overlayed with the macromolecular species binding member. Alternatively, the macromolecular species binding member may be adapted such that it overlays the tape when the tape is still mounted on the cylindrical member.

Many types of objects may be sampled by the device of the present invention including but not limited to a solid table top or floor, a fibrous or porous surface such as clothing or carpet or other areas such as a bed or other types of furniture. In addition to surfaces where particulate matter such as dust naturally accumulates, it may be desirable to sample dust areas to which dust has been specifically attracted such as the metal collection plates of an electrostatic air sampler. Samples may also be collected from the surface of animate or inanimate objects. For example, the surface of a human or an animal may be sampled for detection of organisms of diagnostic or pathological interest. Specifically, inflamed skin may be sampled to determine the presence of Dermatophyte fungi. Food preparation areas may be sampled to determine the presence of pathogenic organisms. In a second aspect, the present invention provides a method of sampling particulate matter using the device of the first aspect, the method including the steps of:

(i) applying the face of the adhesive member to the object to be sampled such that particulate matter present on the object adheres to the face of the adhesive member;

(ii) removing the face of the adhesive member from the object; and (iii) overlaying at least a portion of the face of the adhesive member with the macromolecular species binding member, such that any particulate matter which has adhered to the face of the adhesive member is held between the adhesive member and the macromolecular species binding member.

In one embodiment of the second aspect, the at least one portion of the face of the adhesive member may be overlayed with the macromolecular species binding member immediately following sampling of a surface. Alternatively, a protective film may be temporarily placed over the face of the adhesive member with the step of overlaying with the macromolecular species binding member occurring later. By covering the adhesive member with the protective film, the likelihood of contamination with particles which are not from the sampled surface is reduced.

Preferably, the entire face of the adhesive member is overlayed by the macromolecular species binding member.

The sampling by adhesive contact may be performed in numerous ways. For example, at least a portion of the face of the adhesive member may be stamped onto the object to be sampled. The face of the adhesive member may also be pressed onto the same area of the object once or multiple times or alternatively may be pressed onto different areas of the object once or multiple times.

In a third aspect, the present invention provides a device for the sampling of particulate matter, the device including an adhesive member hingedly connected to a macromolecular species binding member such that both members are movable relative to each other from a first open position to a second closed position and wherein, in the first open position, particulate matter from the surrounding environment is allowed to settle on a sampling face of the adhesive member and a sampling face of the macromolecular species binding member and wherein in the second closed position, said particulate matter is held between the adhesive member and the macromolecular species binding member.

In an embodiment of the third aspect, the particulate matter sampled settles on the sampling surface of both the adhesive member and the macromolecular species binding member by way of gravity. Preferably, the adhesive member and the macromolecular species binding member of the third aspect are hingedly connected to each other by a support member. Typically, both the adhesive member and the macromolecular species binding member are mounted on the support member which is made from a light cardboard or plastic although other materials are envisaged. Preferably, the adhesive member and the macromolecular species binding member are covered by respective removable protective films which may be removed immediately prior to use of the device.

In the first open position, preferably the adhesive member and the macromolecular species binding member lie in substantially the same horizontal plane relative to each other and preferably such that the two members lie flat upon the same surface.

As with the previous aspects, the adhesive member is typically an adhesive tape, said sampling surface being the adhesive side of the tape.

One or both of the adhesive member and/or the macromolecular species binding member may have further properties to enhance the capture of particulate matter such as a passive electrostatic charge.

In a fourth aspect, the present invention provides a method of sampling particulate matter using the device of the third aspect, the method including the steps of: (i) moving the adhesive member and the macromolecular species binding member into the first open position such that a sampling face of both members is exposed to the environment;

(ii) leaving the device in the second open position for a predetermined period of time; (iii) moving the device into the second closed position such that the sampling face of both members are brought together thereby trapping any sampled particulate matter between the adhesive member and the macromolecular species binding member.

The pre-determined sampling period of the fourth aspect of the invention may be determined by several factors including location of the device. Typically, it is envisaged that the device is left in an open position for a week although sufficient particulate matter may be collected in a day in some situations.

In relation to each of the above aspects, a "sandwich" formed from the adhesive member, any particulate matter sampled and the macromolecular species binding member may be excised from the support member and subjected to a suitable immunoassay system.

Suitable assay systems include but are not limited to the immunoassay system described in US Patent No 5955376 and International Patent No PCT/AU99/00017, the contents of which are herein incorporated by reference.

The assays described in these documents are hereinafter referred to as "halogen assays" and are further described in De Lucca, S., O'Meara, T., and Tovey, E. "Exposure to mite and cat allergens on a range of clothing items at home and the transfer of cat allergen in the workplace" /. Allergy Clin. Immunol. 2000; 106(5): 874-9 and Razmovski V, O'Meara TJ, Taylor DJM, Tovey ER, "A new method for simultaneous immunodetection and morphologic identification of individual sources of pollen allergens", /. Allergy and Clin Immunol. (2000) 105: No. 4, 725-31.

The selected assay and its results may be performed and expressed in several ways. For example, for some purposes it may be convenient to count the total number of particles carrying allergens, as determined by the halos of immunostain produced using an allergen-specific primary antibody. This may be expressed as a function of the area of the face of the adhesive member (or additionally the macromolecular-species binding member in relation to the device of the third and fourth aspects) per item sampled or per area sampled. For other purposes it may be convenient to express the number of particles containing allergen as the proportion of the total number of particles collected. Other primary antibodies may be used, for example, IgE from an allergic subject, to give an index of an individual's response to their own environment. In all cases, both the size of the particles can be measured and the size and intensity of the individual immunostained "halos" can be measured.

It is further envisaged that the above aspects of the invention may be combined. For example, any particulate matter which has settled onto the device of the third aspect could be sampled by the face of the adhesive member of the device of the first aspect.

In a fifth aspect, the present invention consists in a device for sampling particulate matter, the device including:

(a) an adhesive or adsorptive surface for sampling particulate matter; (b) a multi-functional layer adapted to overlay at least a portion of the adhesive or adsorptive member, said multi-functional layer being removable from the device prior to sampling and replaceable after sampling;

(c) a receiving region for receiving liquid required for immunoassay of the sampled particulate matter;

(d) a collection region in which said liquid is held for subsequent immunoassay; and

(e) a housing onto which elements (a) to (d) are mounted.

The adhesive or adsorptive surface may comprise an adhesive tape or alternatively, a non-porous adsorptive surface or a porous absorptive material such as fibrous material or a cloth including an electrostatic cloth. In the latter case, it is preferred that the electrostatic cloth is wettable.

The receiving region for receiving liquid may be a porous pad. The liquid added may be buffer or other liquid to allow immunoassay of the sampled particulate matter.

The receiving region may contain components which facilitate the migration of liquid, extraction of allergens and may include components of a subsequent immunoassay.

The multi-functional layer may be removed prior to sampling the particulate matter and replaced after sampling. The purpose of the layer is both to protect the dry adhesive or adsorptive surface prior to sampling and to provide one part of a channel for the later extraction of allergen from the sampled particulate matter.

In a sixth aspect, the present invention provides a method of sampling particulate matter for subsequent immunoassay using the device of the fifth aspect, the method including the steps of:

(i) removing the multi-functional layer from the device such as to expose the adhesive or adsorptive surface;

(ii) pressing the adhesive or adsorptive surface against a surface to be sampled until said surface is sufficiently coated with particulate matter;

(iii) replacing the multifunctional layer such that it overlays at least a portion of the adhesive or adsorptive surface, trapping the sampled particulate matter therebetween;

(iv) adding the liquid required for immunoassay to the receiving region and allowing the liquid to move from the receiving region to the sample of particulate matter; and (v) allowing the liquid to move from the sample of particulate matter to the collection region.

The liquid may act to extract the soluble components of the particulate matter from the sample. In this embodiment, the liquid typically travels by capillary action through the receiving region and onto the adhesive or adsorptive surface containing the sample of particulate matter.

Both the nature of the adhesive or adsorptive surface and the multifunctional layer are preferably such as to allow the process of capillary migration of the liquid. The liquid typically then moves from the sample of particulate matter to the collection region.

While the movement of liquid may be by capillary action it should be noted that the invention is not limited to such action and other means of causing the liquid to move are envisaged. For example, the device may include a roller member adapted to roll across the surface of the receiving region and/or the adhesive or adsorptive surface thereby forcing the liquid from the receiving region to the adhesive or adsorptive surface and/or from the adhesive or adsorptive surface to the collection region.

Alternatively, the entire adhesive or adsorptive surface may be removed from the device and subjected to centrifugation to recover the liquid containing the soluble components of the particulate matter. The recovered eluate may then be transferred to the collection region for subsequent immunoassay. In this embodiment, it is envisaged that the collection region contains an immunoassay. As noted above, the collection region may contain an immunoassay, such that the quantity or identity of the soluble materials in the sample are directly measured and identified. Alternatively, the collection region may be removed and the liquid extracted and transferred to another assay system.

Different methods of transfer could be used, for example the collection region may consist of a receiving region from which the liquid could be recovered, by for example centrifugation; or the liquid could directly be transferred to another assay by capillary action.

This system has several advantages over currently used systems of sampling surfaces with a vacuum cleaner and extracting portions of the collected particulate matter for immunoassay. Preferably, the device of this aspect provides a small and simple device which can be used to quantitatively sample different sources of allergenic particles such as clothing, beds, carpets or floors. This may be performed by repeatedly pressing the sampler on the surface to be sampled. Particles can also be attracted onto the surface by other means such as aeroallergen impaction occurring in specialised device or within an item such as a holder designed for this purpose fitting into a vacuum cleaner's tubing, and aeroallergen settling and aeroallergen sampling using electrostatic attraction. The quantitative nature of the sampler is typically created by the limitation of the adhesive or adsorptive surface to bind any more particles once the surface is saturated. After sampling, the device provides a new way to extract the collected particulate matter in a limited volume of liquid. It allows different components to be added to this extraction process. Finally, the device allows integration into other assay systems without the need to remove contaminating particulates which might otherwise interfere with the assay. In a seventh aspect, the present invention consists in a device for sampling particulate matter, the device including:

(a) an adhesive or adsorptive surface for sampling particulate matter and;

(b) a permeable layer adapted to overlay at least a portion of the adhesive or adsorptive surface; wherein said adhesive or adsorptive surface together with said permeable layer are capable of being rolled or folded together following sampling of the particulate matter such that components of the sample of particulate matter are caused to move from the adhesive or adsorptive surface to the permeable layer.

Preferably, the adhesive or adsorptive surface is made from a non- macromolecular binding material. The adhesive or adsorptive surface may be made from, but is not limited to, a material such as the adhesive tapes previously referred to in Razmovski (2000) or may be an electrostatically adhesive such as the membrane Electret™. The adsorptive layer may be a porous matrix such as a cloth or an electrostatic cloth and, preferably a wettable electrostatic cloth.

Further, it is preferred that the permeable layer is made from a non- macromolecular binding material. Typically, the permeable layer is treated with a solution which aids the solubilisation of allergens in the sampled particulate matter. The permeable layer may be made from a material such as tissue paper which has previously been treated with a non-specific protein solution, such as BSA.

Preferably, when the adhesive or adsorptive surface and the permeable layer are rolled or folded together, at least a portion of the permeable layer extends beyond the adhesive or adsorptive surface wherein said at least a portion may be placed into a source of liquid. The permeable layer allows the capillary movement of the liquid from the source through the permeable layer. As the liquid moves through the permeable layer, allergens present in the sampled particulate matter may be eluted from the adhesive or adsorptive surface and into the liquid. The eluted allergens may then be recovered from the liquid.

The liquid may be recovered either by centrifugation of the adhesive or adsorptive surface and the permeable layer or by capillary action directly into a rapid assay device. In the latter case, additional liquid may be required to 'chase' the liquid through.

In an eighth aspect, the present invention consists in a method of sampling particulate matter for subsequent immunoassay using the device of the seventh aspect, the method comprising the steps of:

(a) collecting particulate matter on to the surface of the adhesive or adsorptive surface;

(b) overlaying the permeable layer over at least a portion of the adhesive or adsorptive surface;

(c) rolling or folding the adhesive or adsorptive surface together with the permeable layer such that at least a portion of the permeable layer extends beyond an end of the adhesive or adsorptive surface;

(d) placing said portion of the permeable layer into a source of liquid such that liquid is drawn into the permeable layer and wherein soluble components of the sampled particulate matter are caused to move from the adhesive or adsorptive surface and into the liquid; and (e) recovering the soluble components from the liquid. Brief Description of the Drawings

Figure 1 is a schematic view of an embodiment of one aspect of the invention.

Fig ire 2 is a cross-sectional side schematic view of the invention depicted in figure 1. Figure 3 is a further cross-sectional side schematic view of the invention depicted in figure 1.

Figure 4 is another cross-sectional side schematic view of the invention depicted in figure 1. Figure 5 is a schematic view of another embodiment of the aspect of the invention depicted in Figure 1.

Figures 6 to 12 are cross-sectional side views depicting the general principles of sampling of the present invention.

Figure 13 is a cross-sectional side view of another aspect of the invention in a closed position.

Figure 14 is a cross-sectional side view of the invention depicted in Figure 13 when in use and in an open position.

Figure 15 is a further a cross-sectional side view of the invention depicted in Figures 13 and 14 when in use and in an open position. Figure 16 is a schematic view of the invention depicted in Figures 14 and 15.

Figure 17 is another cross-sectional side view of the invention depicted in Figures 13 to 16 when in use and in a closed position.

Figure 18 shows a device for rapid sampling and assay of reservoir dust samples.

Figure 19 shows a device of a further aspect of the invention for sampling particulate matter. Description of invention

The sampling device 10 of the present invention includes an adhesive member 11 and a macromolecular binding membrane 12. The adhesive member 11 includes a support member 13 and an adhesive tape 14 which, when in use, may be pressed against a surface or object to be sampled. When not in use, the adhesive tape 14 is protected by way of a thin film 15 or other suitable means. The protein binding membrane 12 includes a support member 16 and a face 17. Again, when not in use, the face 17 of the protein binding membrane 12 is protected by a protective flap 18.

The support member 13 and the support member 16 are hingedly connected at hinge 19 such that the adhesive member 11 and the protein binding membrane 12 may be moved between a closed position relative each other as depicted in Figures 2 and 4 to a second open position as depicted in Figure 3. The support member 13 and the support member 16 may be a unitary member with its main function being to enable hinged movement as discussed above but also to provide a physical structure to support the operation of the adhesive member and the protein binding membrane. Suitable materials include paper, cardboard and plastic of different types. In use, the thin film 15 is peeled away to expose the adhesive tape 14.

The adhesive tape 14 is then used to sample particulate matter on an object or surface. In this regard, the tape is selected for its ability to bind particles as well as its suitability for subsequent participation in an immunoassay.

Figures 8, 9 and 10 show the adhesive tape 14 being used to collect particulate matter 21 by forming a temporary contact between an object to be sampled 22 and the adhesive tape 14, such that the particulate matter 21 is removed from the surface and wherein the particulate matter 21 adheres to the adhesive tape 14 once removed.

This sampling by adhesive contact, can be performed in numerous ways. For example, a flat section of the adhesive tape 14 may be stamped onto the surface to be sampled. Alternatively, a cylinder 23 covered with the adhesive tape 14 may be rolled across the object as depicted in Figure 5.

The device 10 of the present invention is used to sample many types of surfaces or objects including table tops or floors, or fibrous or porous surfaces, for example, clothing or carpet. In addition to surfaces where particulate matter naturally accumulates, it may be desirable to sample areas to which s ich matter has been specifically attracted to such as the metal collection plates of an electrostatic air sampler. Samples may also be collected from the surface of animate or inanimate objects. For example, the surface of a human or an animal may be sampled for detection of organisms of diagnostic or pathological interest - for example, inflamed skin may be sampled to determine the presence of Dermatophjrte fungi. Food preparation areas may be sampled to determine the presence of pathogenic organisms. After sampling has been performed, the protective flap 18 is folded back and the face 17 of the protein binding membrane 12 is brought into contact with the adhesive tape 14 bearing the particulate matter 21, as shown in Figure 12. Accordingly, the particulate matter 21 is sandwiched between the adhesive member 11 and the protein binding membrane 12.

While it may be convenient to form such a "sandwich" immediately, film 15 may be temporarily replaced onto the adhesive tape 14, with overlay with the protein binding membrane 12 occurring later. Covering the adhesive tape 14 prevents contamination with particles which are not from the sampled object.

The protein binding membrane is selected for its compatibility with the reactions of an assay system. Suitable membranes may include nitrocellulose, PVDF and nylons, as used in immunoblotting (Protein blots, Western blots) applications.

Once the steps of sampling and overlay with the protein binding membrane 12 have occurred, the above described "sandwich" may be removed from the base members 13 and 16 and processed through an immunoassay system. The assay may be performed by using a series of incubations where passage of the reactants occurs essentially tangentially through the membrane walls and where the total assay time occupies several hours, or alternatively performed in a different form where the where passage of reactants occurs longitudinally through the membrane by immuno- chromatographic assay systems. This reduces the incubation times.

The size (surface area and shape) of adhesive tape 14 and the sampling protocol will be dictated by various criteria including the performance of the sampling, the density of particles on an object and the means of immunoassay available. For example, for sampling a surface such as clothing or bedding, an area of adhesive tape 14 approximately 3 cm x 3 cm in size is convenient.

A second means of collecting samples of particulate matter utilises device 30 (see Figs. 13-17) which is formed of an adhesive member 31 and a protein binding membrane 32 mounted on a support member 33. In this embodiment, the support member 33 is hingedly connected at hinge 34 such that both members 31 and 32 are movable relative each other from a first closed position depicted in Figures 13 and 17 to a second open position depicted in Figures 14, 15 and 16.

Essentially, the same general principles as described above apply to this aspect of the invention except that the adhesive member 31 and the protein binding membrane 32 are not brought into contact with an object to be sampled. Rather, particulate matter 37 is collected on face 35 of the adhesive member 31 and face 36 of the protein binding membrane 32 as it settles out by way of gravity from the surrounding environment. Prior to sampling, the two members 31 and 32 are in the closed position. To initiate sampling, the members are moved to the open position and a protective layer 38 removed from the adhesive member 31 as shown in Figure 14. For performing sampling, the device 30 is left in the open position in a suitable and preferably flat location so that airborne particulate matter 37 can settle from the surrounding air onto face 35 and face 36 of the adhesive member 31 and the protein binding membrane 32 respectively, as shown in Figures 15 and 16. After the period of sampling, the device is moved into the closed position as depicted in Figure 17. The "sandwich" of adhesive member 31, particulate matter 37 and protein binding membrane 32 can be excised from the supporting member 33 and subjected to an immunoassay system as previously described.

The length of the sampling period is determined by the location and level of exposure. Typically, a device 30 with adhesive member 31 and protein binding membrane 32 having dimensions of 36 mm x 36 mm when placed for a week in an open location in a house, such as on top of a shelf oibeside a bed, will collect sufficient particles carrying allergen for assay of house dtist mite and cat allergens.

This type of sampling would normally be performed indoors and the quantity of such aeroallergen collected under standardised conditions would be considered an index of human exposure occurring in this environment. The device 50 of Figure 18 is shown as an exploded view in Figure 18a and in a side view in Figure 18b. The device 50 consists of a dry adhesive or adsorptive surface 51 which is used to sample dust together with a multifunctional layer 52 which may be removed prior to sampling the dust and replaced after sampling. The purpose of the multi-functional layer 52 is both to protect the adhesive or adsorptive surface 51 prior to sampling and to provide one part of a channel for the later extraction of allergen. The device 50 further includes a porous area 53 which is used as the site for the addition of buffer or liquid to initiate an immunoassay in area 54. The porous area 53 may comprise a receiving region and, further, may contain components which facilitate the migration of liquid, extraction of allergens and may include components of a subsequent immunoassay. The liquid may be recovered from the immunoassay area 54 for external assay by other means or, alternatively, the immunoassay area 54 may contain an internal immunoassay to identify and/or measure components contained by the sample. A platform 55 onto which the different components are mounted forms part of the device. The process of using the device 50 is shown in Figures 18c to 18k. Figure 18c shows removal of the multi-functional layer 52. Figure 18d shows sampling of the dust source until the adhesive or adsorptive layer 51 is coated with dust. In Figure 18f, the multi-functional layer 52 is replaced. In Figure 18g the liquid for extraction of the soluble components of the dust is added to porous area 53. The liquid travels by capillary action through the porous area 53 and into a channel 56 containing the dust sample (Figure 18h). The boundaries of channel 56 are formed by the multifunctional layer 52 and the adhesive or adsorptive layer 51. During this process the soluble materials are extracted from the sample, Figure 18i. Both the nature of the adhesive or adsorptive layer 51 and of the multi-functional layer 52 should to be suitable for the process of capillary migration of liquid to occur.

The liquid then enters the immunoassay area 54 as shown by the arrows in Figure 18k. In this regard, two options are possible: immunoassay area 54 may contain an immunoassay, such that the quantity or identity of the soluble materials in the sample are directly measured and identified. This is depicted in Figure 18j showing inbuilt assay 57. In another case immunoassay area 54 may contain a region which can be removed and the liquid extract transferred to another assay system as depicted in Figure 18i. Different methods of transfer could be used - for example immunoassay area 54 could consist of a receiving region from which the liquid could be recovered, by for example centrifugation; or the liquid could directly be transferred to another assay by capillary action. In a further aspect, the present invention consists in a device generally depicted as 60 in Figure 19.

The device 60 includes an adhesive or adsorptive surface 61 for sampling particulate matter and a permeable layer 62 adapted to overlay at least a portion of the adhesive or adsorptive surface 61. The adhesive or adsorptive surface 61 together with the permeable layer 62 are rolled together following sampling of particulate matter.

As depicted in Figure 19c, when the adhesive or adsorptive surface 61 and the permeable layer 62 are rolled together, at least a portion 63 of the permeable layer 62 extends beyond the adhesive or adsorptive surface 61. As shown in Figure 19d, this portion 63 is placed into a source of liquid and the liquid drawn up through the permeable layer 62. As the liquid moves through the permeable layer 62, allergens present in the sampled particulate matter are eluted from the adhesive or adsorptive surface 61 and into the liquid.

The liquid is recovered by centrifugation of the adhesive or adsorptive surface 61 and the permeable layer 62 for later assay as depicted in Figure 19f or recovered by capillary action into rapid assay as depicted in Figure 19g.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A device for sampling particulate matter present on an object, the device including an adhesive member and a macromolecular species binding member wherein the adhesive member includes a face for contacting an object and for binding said particulate matter present on the object and wherein further, the macromolecular species binding member is adapted to overlay at least a portion of the face of the adhesive member following sampling.

2. The device of claim 1 wherein the adhesive member is adhesive tape having an adhesive surface and a back surface and wherein the face of the adhesive member is the adhesive surface of the tape.

3. The device of claim 1 or claim 2 wherein the macromolecular species binding member is a protein binding membrane.

4. The device of claim 3 wherein the protein binding membrane is selected from the group comprising nitrocellulose, PVDF and nylons.

5. The device of any one of the preceding claims wherein both the adhesive member and the macromolecular species binding member are mounted on a support member which is made from a material selected from the group comprising paper, cardboard or plastic.

6. The device of any one of the preceding claims wherein the adhesive member and the macromolecular species binding member are hingedly connected to each other such that each member may be moved between a first closed position relative to each other and a second open position relative to each other.

7. The device of claim 5 wherein the support member is hinged such that it forms a book-like structure

8. The device of claim 1 wherein the adhesive member is mounted on a cylindrical member.

9. The device of claim 8 wherein the adhesive member is detachably mounted on said cylindrical member.

10. The device of any one of the preceding claims for sampling particulate material present on solid table tops, floor, fibrous or porous surfaces such as clothing or carpet or other areas such as a bed or other types of furniture.

11. A method of sampling particulate matter using the device of claim 1, the method including the steps of: (i) applying the face of the adhesive member to the object to be sampled such that particulate matter present on the object adheres to the face of the adhesive member;

12. The method of claim 11 wherein the at least one portion of the face of the adhesive member is overlayed with the macromolecular species binding member immediately following sampling of a surface.

13. The method of claim 11 including the further step of applying a protective film temporarily over the face of the adhesive member prior to the step of overlaying the face of the adhesive member with the macromolecular species binding member.

14. The method of any one of claims 11 to 13 wherein the entire face of the adhesive member is overlayed by the macromolecular species binding member.

15. The method of any one of claims 11 to 14 wherein the sampling by adhesive contact is performed by pressing the face of the adhesive member onto an object to be sampled.

16. A device for the sampling of particulate matter, the device including an adhesive member hingedly connected to a macromolecular species binding member such that both members are movable relative to each other from a first open position to a second closed position and wherein, in the first open position, particulate matter from the surrounding environment is allowed to settle on a sampling face of the adhesive member and on a sampling face of the macromolecular species binding member and wherein in the second closed position, said particulate matter is held between the adhesive member and the macromolecular species binding member.

17. The device of claim 16 wherein the adhesive member and the macromolecular species binding member are hingedly connected to each other by a support member.

18. The device of claim 16 wherein when in the first open position, the adhesive member and the macromolecular species binding member lie in substantially the same horizontal plane relative to each other.

19. The device of any one of claims 16 to 18 wherein the adhesive member is an adhesive tape and wherein the sampling surface is the adhesive face of the tape.

20. The device of any one of claims 16 to 19 wherein one or both of the adhesive member and the macromolecular species binding member have further properties to enhance the capture of particulate matter including having a passive electrostatic charge.

21. A method of sampling particulate matter using the device of claim 16, the method including the steps of:

(i) moving the adhesive member and the macromolecular species binding member into the first open position such that a sampling face of both the adhesive member and the macromolecular species binding member is exposed to the environment;

(ii) leaving the device in the second open position for a predetermined period of time;

(iii) moving the device into the second closed position such that the sampling face of both members are brought together thereby trapping any sampled particulate matter between the adhesive member and the macromolecular species binding member.

22. The method of claim 21 wherein the device is left in the open position for at least a week.

23. The method of any one of claims 11 to 15 and claims 21 or 22 wherein the adhesive member, any particulate matter sampled and the macromolecular species binding member form a sandwich member which is excised from the support member and subjected to immunoassay.

24. The method of claim 23 wherein the assay is selected from the group comprising Halogen assay or similar assay involving the direct or indirect capture of extracted macromolecules by a macromolecular binding membrane or other solid phase, including by specific antibodies linked to such a membrane.

25. A device for sampling particulate matter, the device including: (a) an adhesive or adsorptive surface for sampling particulate matter; (b) a multi-functional layer adapted to overlay at least a portion of the adhesive or adsorptive member, said multi-functional layer being removable from the device prior to sampling and replaceable after sampling;

(e) a housing onto which elements (a) to (d) are mounted.

26. The device of claim 25 wherein the receiving region for receiving liquid is a porous pad or cavity.

27. The device of claim 25 or claim 26 wherein the liquid is buffer or a liquid to allow a subsequent immunoassay of the sampled particulate matter.

28. The device of claim 26 wherein the porous receiving region contains components which facilitate the migration of liquid and/or extraction of allergens and/or includes components of a subsequent immunoassay.

29. A method of sampling particulate matter for subsequent immunoassay using the device of claim 25, the method including the steps of:

(i) removing the multi-functional layer from the device such as to expose the adhesive or adsorbent surface; (ii) pressing the adhesive or adsorptive surface against a surface to be sampled until said surface is sufficiently coated with particulate matter;

(iii) replacing the multifunctional layer such that it at least substantially overlays the adhesive or adsorptive surface, trapping the sampled particulate matter therebetween; (iv) adding the liquid required for immunoassay to the receiving region and allowing the liquid to move from the receiving region to the sample of particulate matter; and

(v) allowing the liquid to move from the sample of particulate matter to the collection region.

30. The method of claim 29 wherein the liquid carries soluble components of the particulate matter from the sample to the collection region.

31. The method of claim 29 or claim 30 wherein the liquid is caused to travel by capillary action.

32. The method of any one of claims 29 to 31 wherein the liquid is collected from the collection region for subsequent immunoassay.

33. The method of any one of claims 29 to 31 wherein the liquid undergoes immunoassay in the collection region.

34. A device for sampling particulate matter, the device including:

(a) an adhesive or adsorptive surface for sampling particulate matter and;

(b) a permeable layer adapted to overlay at least a portion of the adhesive or adsorptive surface; wherein said adhesive or adsorptive surface together with said permeable layer are capable of being rolled oτ folded together following sampling of the particulate matter such that components of the sample of particulate matter are caused to move from the adhesive or adsorptive surface to the permeable layer.

35. The device of claim 34 wherein the adhesive or adsorptive surface is made from a non-macromolecular binding material.

36. The device of claim 34 or claim 35 wherein the adhesive or adsorptive surface is a wettable matrix including a wettable electrostatic cloth.

37. The device of any one of claims 34 to 36 wherein the permeable layer is made from a non-macromolecular binding material.

38. The device of any one of claim 34 to 37 wherein the permeable layer is treated with a solution which aids the solubilisation of allergens in the sampled particulate matter.

39. The device of any one of claims 34 to 37 wherein the permeable layer is made from a material which has previously been treated with a non-specific protein solution.

40. The device of any one of claims 34 to 39 wherein when the adhesive or adsorptive surface and the permeable layer are rolled or folded together, at least a portion of the permeable layer extends beyond an end of the adhesive or adsorptive surface.

41. A method of sampling particulate matter for subsequent immunoassay using the device of the claim 34, the method comprising the steps of:

(b) overlaying the permeable layer over at least a portion of the adhesive or adsorptive surface; (c) rolling or folding the adhesive or adsorptive surface together with the permeable layer such that at least a portion of the permeable layer extends beyond an end of the adhesive or adsorptive surface;

(d) placing said portion of the permeable layer into a source of liquid such that liquid is drawn into the permeable layer and such that soluble components of the sampled particulate matter are caused to move from the adhesive or adsorptive surface and into the liquid; and

(e) recovering the soluble components from the liquid.