WO2011105884A2

WO2011105884A2 - Apparatus and method for distributing liquid samples in small volumes

Info

Publication number: WO2011105884A2
Application number: PCT/MX2011/000032
Authority: WO
Inventors: José Carlos BARRENECHEA OAR; Raúl GRANDE GUTIERREZ
Original assignee: Barrenechea Oar Jose Carlos; Grande Gutierrez Raul
Priority date: 2010-02-22
Filing date: 2011-02-22
Publication date: 2011-09-01
Also published as: WO2011105884A3

Abstract

The invention relates to an apparatus for distributing liquid samples in small volumes, comprising a preformed rigid channel made from non-permeable material and including an inlet and one or more outlets, characterised in that the dimensions of the channel vary along the length thereof, forming interconnected conduits, branches and containers. The invention also relates to the production method thereof.

Description

APPARATUS AND METHOD FOR DISTRIBUTING LIQUIDS SAMPLE IN

SMALL VOLUMES

Field of the Invention The invention consists of a rigid and preformed duct of non-permeable material, with an inlet and one or more outlets in which, due to gravity and air displacement, automatic distribution of liquids shown in preformed tanks or compartments is achieved in the same pipeline. The dimensions of the pipeline vary throughout it, forming communicating ducts, deposits and, where appropriate, bifurcations. The pipeline is located in such a way that the entrance and the exit (s) are at a higher level and below it, two or more deposits equal or not to each other which can be located:

A) INDEPENDENTLY: Each tank has a communicating duct between itself and the liquid inlet shows as well as an outlet duct for the displaced air that reaches the top of the apparatus

B) FORMING SERIES: Two or more deposits communicated with each other through ducts where not all deposits have ducts that communicate directly to the upper entrance of the sample liquid and to the air outlet displaced in the upper part of the device.

The dimensions of the deposits are calculated based on the total number of parts in which it is desired to divide the sample, the total volume of the sample and quantity of air and liquid shows that it is desired to leave in each of the deposits and even the geometric shape that you want to use for each deposit, these being the same or different from each other.

The level of height at which the communicating ducts enter and leave the tanks is determined by the required proportion or percentage of sample liquid and air that is desired to remain in each of them and may even leave it without air. Said level can be the same in all the deposits or different between them, depending on the needs of the user and is calculated taking into account the device in an upright position.

The communicating ducts can always be located on the same side in all the tanks in such a way that when the device is laid on the opposite side where the ducts are located, the liquid shown by gravity effects is evacuated from the communicating ducts and housed in the tanks, leaving the liquid shows, in addition to divided, totally separated and independent.

If it is required to vary the proportion of the sample liquid and air, it is sufficient to vary the angle of inclination of the apparatus when receiving the sample liquid.

BACKGROUND OF THE INVENTION In the field of medicine, biology and microbiology, there are various analysis and culture techniques that require the orderly separation of liquid samples into smaller parts and that require, in most cases, a hard work, time consuming = o require equipment that is too sophisticated and expensive to carry out.

Likewise, the diversity of organisms that can be studied is as great, and the requirements for the best development of each of them are as different as their metabolic characteristics. An example of these differences is in the effect that 02 generates on its. Growth and metabolism. These properties are important for the pathogenesis and for the isolation and Identification of the organism by grouping them as follows:

1. - strict aerobic: they need oxygen and lack the ability to carry out fermentation.

2. - strict anaerobes that can only grow in the absence of oxygen,

3. - facultative organisms: that grow both in the presence of oxygen and in the absence of it and pass in the presence of air, to a respiratory type metabolism.

4. - Aerotolerant anaerobes: which can grow in the presence or absence of oxygen, but their metabolism is always fermentative.

This is why the presence or absence of air in their cultivation sites can be very important for their optimal development.

In microbiology, the most commonly used methods for the quantification of bacteria and other microorganisms in water are that of Membrane Filtration and the Most Probable Number (NMP) Method. The first, somewhat more limited than the second because of its difficulty in quantification when the number of colonies is very high. The NMP procedure is based on a statistical estimate of the number of bacteria per unit volume and is determined by the number of positive results in a series of tubes or tanks incubated. The greater the number of deposits incubated, the greater the accuracy of the results obtained. Also, when the bacterial counts are very high, this method allows dilutions to be made to find effective readings that allow a clear idea of the bacterial density of the sample liquid.

A simple and quick method to separate the liquid shows in many small homogeneous portions as well. as the possibility of counting or not, depending on the case with air in each of the tanks or culture compartments is very useful to achieve optimal results.

The estimation of bacterial density by means of the NMP method can be done in two ways, one that is the determination by means of multiple tubes as described in the "Standard Methods for the Examination of Water and Wastewater" using test tubes performing the separation of the sample liquid manually by means of pipettes or similar apparatus and also using the method described in US Pat. 5,518,892, US 5,620,895, US 5,753,456. In said patents an apparatus is used for the separation of the sample consisting of a bag in which the sample liquid is divided by the mechanical action of rollers that at the same time provide the heat necessary to adhere a film to the rigid side of the bag achieving the total separation of the sample. This option does not allow the alternative of leaving a specific volume of air in each of the aliquots and also requires special equipment for its division and separation.

The apparatus in relation to this patent contains the following differences:

It is a preformed, waterproof and rigid duct that performs, by the sole action of gravity and air displacement, the automatic distribution of the liquid shows in two or more tanks leaving in each of the tanks (or compartments) an amount of liquid and default air. It has the advantage that a certain volume of air can be left with the simple fact of varying the height of the displaced air outlet in each compartment, so it can be used for the detection of microorganisms whose metabolism works best with or without oxygen (air volumes can vary from 0% to the percentage required to have deposits).

Another advantage is that, in the case of the tanks containing sufficient air and also the design of the tanks being adequate, the liquid of each tank is separated from the rest with the simple fact of laying down or turning said apparatus. The separation between the compartments could also be obtained with the simple sealing of the communicating ducts that have the deposits with each other by applying pressure and heat at specific points.

Description of the drawings

Figure 1.- A figure is shown with a vertical front view in which independent deposits are observed with the following components: a. - Communicating channels

b.- Sample entry duct,

c- Independent Deposits

d. - Air ducts displaced

and. - Volume of the sample liquid

f. - Air volume Figure 2.- A figure is shown with a vertical front view of the pipeline with series deposits in which the following components are observed: a. - Communicating channels

b. - Sample inlet duct,

c- Deposits in series

d.- Air ducts displaced

e.- Volume of the sample liquid

f. - Air volume

Figure 3. - It shows that two or more series can be integrated to achieve a greater number of independent tanks, each series with its independent outlet duct.

Figure 4. Shows the location, on one side, of the deposits. In order to evacuate the communicating ducts, these can be located on the side of the tanks in such a way that when the device is rotated, the liquid contained in them due to gravity, is evacuated from the communicating ducts and housed in the tanks achieving in addition to the division the complete separation of the liquid sample. Figure 5. - Shows a view of a first embodiment of the present invention.

Figure 6.- Shows a view of a second embodiment of the present invention.

Detailed description of the invention.

The invention consists of a rigid and preformed duct of non-permeable material, with an inlet and one or more outlets in which, due to the effects of gravity and air displacement, the automatic distribution of liquids shown in preformed tanks or compartments is achieved. pipeline The dimensions of the pipeline vary along it, forming communicating ducts, bifurcations and deposits, which are located in such a way that they allow a controlled flow of air and the accommodation of the liquid shows in the deposits formed within it. The pipeline is located in such a way that the entrance and the exit (s) are at a higher level and below it, two or more deposits equal or not to each other which can be located: A) INDEPENDENTLY: Each tank has a communicating duct between itself and the liquid inlet shows as well as an outlet duct for the displaced air that reaches the top of the apparatus

B) FORMING SERIES: Two or more tanks connected to each other through ducts, where not all tanks have ducts that communicate directly to the entrance of the sample liquid and to the outlet of the air displaced in the upper part of the device. The arrangement of these series of tanks can be vertical, horizontal or combined according to the design of the device. Two or more series of deposits can be used in the same device.

The dimensions of the deposits are calculated based on the total number of parts in which you want to divide the sample, the total volume of the sample and the amount of air and liquid that you want to leave in each of the deposits and even the shape geometric that you want to use for each deposit and these can be the same or different from each other. The level of height at which the communicating ducts enter and leave the tanks is determined by the required proportion or percentage of sample liquid and air that is desired to remain in each of them and may even leave it without air. Said level can be the same in all the deposits or different between them, depending on the needs of the user and is calculated taking into account the device in an upright position.

The communicating ducts can always be located on the same side in all the tanks in such a way that when the device is laid on the opposite side where the ducts are located, the liquid shows by gravity, it is evacuated from the communicating ducts and housed in the tanks, leaving the liquid shows, in addition to divided, totally separated and independent.

If it is required to vary the proportion of the sample liquid and air it is sufficient to vary the angle of inclination of the apparatus upon receiving the sample liquid. The only requirement to achieve this is that all communicating channels are in the same orientation. Finally, from each tank located last considered from the conduit that allows the flow of the liquid shows to each series of intercommunicated deposits or of the independent deposits, another conduit rises up to a higher level and serves to allow the exit of the air surplus of all deposits of said series or deposit.

Deposits should always be located below the level of the entrance to the pipeline as well as the exit (s) thereof, regardless of position.

The dimensions of the deposits and ducts as well as the location of the entrances and exits of the

Communication channels to deposits are defined depending on the following variables;

1. The amount of sample required to analyze

2 . The number of deposits you want to use as well

As the geometric shape.

3. The percentage or proportion of Air that you want to leave in each tank

4. Additionally, if the final closure of communicating channels will be required. Hence :

The dimensions of length, width and height of each tank and ducts can be adjusted to the dimensions most appropriate to the production process, geometric shape or the desired design as long as they have the required volume including the desired amount of air for each tank and considering the device in an upright position.

The sum of the volume of the ducts, the deposits (whether they are equal or not with each other), is equal to the total volume of the sample plus the percentage of air desired.

The height at which the upper part of the communicating ducts of each tank is located is determined by obtaining the level of height that the liquid shown in each tank will take, taking into account the volume of the sample liquid contained in the ducts, placing the latter of preference on the same side of deposits in all cases.

The pipeline is placed vertically, with the liquid inlet shown at the top. The sample liquid is poured into the pipeline and, due to gravity, is distributed in each of the smaller deposits through the lower communicating ducts. The air contained in these, it is displaced by the liquid and leaves through the communicating conduits that rise, allowing the defined filling for each of the deposits. In the case of the tanks that are desired to contain air and it is required to achieve the separation of the samples without the use of other additional equipment, the width of the tanks should be sufficient and proportionally greater than the length thereof, so that By simply laying down the device, the communicating ducts remain at the top of the device, causing the liquid to be located in the ducts, due to gravity, it is dislodged from the ducts and located in the tanks where the final volume of the liquid Sample of each deposit does not reach the level in which the communicating ducts are found thus achieving, in addition to the division, the separation of the liquid sample. Also, the deposits could be definitively insulated by blocking the passage of all the communicating ducts using an apparatus that applies heat and pressure exclusively at specific points of the communicating ducts.

Examples of preferred embodiments or embodiments of the invention. Example 1 (FIGURE 5) of apparatus for quantification of facultative aerobic and anaerobic bacteria by means of NMP 72 Deposits. An example of this apparatus is a duct of a material such as polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyester, ethylene vinyl acetate (EVA), polyethylene (PE), polypropylene (PP) or similar, or a combination of them, thermoplastic or thermofix, transparent, composed of two plates, one of which has a part of the duct thermoformed with the desired shapes and dimensions and the other complementary plate, attached to the first, finishing forming the duct. The design of the duct on the thermoformed plate includes: a larger reservoir for the distribution of the liquid that is located at the top and that has a volume of 100 ml and which in turn has an upper opening through which the sample liquid will be introduced .

It also has 72 deposits equal to each other located in 6 levels, each level with a series of 12 deposits. Each tank has a volume of 1.95 mi and with the following dimensions lcm x 1.2cm x 1.625 cm. The deposits of each level are connected to its neighbor by means of communicating ducts in the form of half a rod with a diameter of 0.7 cm and that are located at a height of 1.15 cm with respect to the bottom of the tank which allows each tank to contain a volume of 1.38 ml of liquid sample and a percentage of 30% of air. The first of the tanks of each series is connected by means of a conduit of diameter of 0.7cm to one of two vertical conduits of 0.7 of diameter that in turn connects them to the greater deposit, the first of these for the first two series and the second for the remaining. For the last of the smaller deposits, and at the same height as the other communicating ducts, a communicating duct in the form of half a cane and 0.3 cm in diameter, goes to the top of the plate which allows the excess air to be allowed allowing hence the flow of the liquid shows through the deposits of the same level.

This thermoformed plate that joins by means of heat and / or pressure and / or an adhesive to a complementary plate leaving the two parts together forming a rigid and waterproof duct.

Finally, by means of a swell, the contour is cut and the communicating conduits that facilitate the air outlet as well as the liquid inlet shows the upper tank. Once finished, it is sterilized to carry out tests such as those of the NMP using specific reagents for each type of microorganism.

The device is placed vertically, with the larger reservoir and liquid inlet shown on the top. The sample liquid is poured into said reservoir and due to the effects of gravity and air displacement, it is distributed in each of the smaller reservoirs through the communicating ducts. The liquid shown in each smaller tank remains in the lower part, allowing the percentage of the desired air to remain inside it, being located above the level at which the communicating ducts are located. The excess air contained in these leaves through the communicating ducts to the neighboring tank and finally through the ducts that rise to the side of the upper tank allowing the distribution of the liquid shown in the smaller deposits.

Once the sample has been distributed in all the tanks and the flow of the sample liquid has stopped, in order to avoid the contact of the sample liquid between the different deposits, just lay the device placing the communicating ducts at the top which will cause the remaining air in each tank to isolate the liquid from them by avoiding contact with the liquid from the adjacent tanks. Also, the deposits could be definitively insulated by blocking the passage of all the communicating ducts using an apparatus that applies heat and pressure exclusively at specific points of the communicating ducts.

Example 2 (FIGURE 6) of an apparatus for quantification of Aerobic and Anaerobic Optional Bacteria by means of MP 75 Communicated, Independent Deposits An example of this apparatus is a pipeline of polyvinylchloride (PVC) material, polyethylene terephthalate (PET), polyester , ethylene vinyl acetate (EVA), polyethylene

(PE), polypropylene (PP) or similar, or a combination thereof, thermoplastic or thermofix, and even coextruded and mixtures or similar, transparent, consisting of two plates, one of which has a thermoformed part of the duct with the shapes and desired dimensions and the other complementary plate, attached to the first, finishing forming the duct. The design of the duct on the thermoformed plate includes: a larger reservoir for the distribution of the liquid that is located at the top and with a volume of 100 ml and which in turn has a top opening through which the sample liquid will be introduced.

It also has 72 deposits equal to each other located in 8 columns, each column with a series of 9 deposits and 3 additional deposits. Each tank has a predetermined volume with a specific liquid and air ratio. The tanks of each level are connected to a contiguous tank by means of communicating conduits that are located at a predetermined height with respect to the lower part of the tank which allows each tank to contain a specific volume of sample liquid and a percentage of air. The first of the tanks of each series is connected by means of a conduit to the horizontal part of the main distribution conduit that exits the greater deposit. On the last of the smaller tanks of each series and at the same height as the other communicating ducts, a communicating duct is released that is connected to the main air outlet duct and from there, towards the top of the apparatus which allows the exit of the excess air thus allowing the flow of the liquid shows through the deposits.

This thermoformed plate that joins by means of heat and / or pressure and / or an adhesive to another complementary plate, leaving the two parts together forming a rigid and impermeable duct.

Finally, the contour is cut by means of a swell and the inlet is opened to the outside where the liquid is poured into the upper tank and the communicating duct that allows the air to escape. Once finished, it is sterilized to carry out tests such as that of the NMP using specific reagents for each type of microorganisms.

The device is placed vertically, with the larger reservoir and liquid inlet shown on the top. The sample liquid is poured into said reservoir and due to the effects of gravity and air displacement it is distributed in each of the smaller reservoirs at different levels through the communicating ducts. The liquid shown in each smaller tank remains in the lower part, allowing the percentage of the desired air to remain inside it when it is located above the level at which it is They find the communicating ducts. The excess air contained in these leaves through the communicating ducts to the tank located above it and finally through the ducts that rise to the main air outlet duct allowing the distribution of the liquid shown in the smaller deposits.

Once the sample has been distributed in all the tanks and the flow of the sample liquid has stopped, in order to avoid the contact of the sample liquid between the different deposits, it is enough to turn the apparatus, placing the communicating conduits in the part upper, which will generate that the liquid shows content in the communicating ducts between the tanks flow and is deposited in the corresponding compartment leaving said duct free of liquid. The liquid sample contained in the main distribution conduit is distributed in the three additional tanks. Finally, the device lies down with the tanks facing down, placing the ducts on the upper face. Also, the deposits could be definitively insulated by blocking the passage of all the communicating ducts using an apparatus that applies heat and pressure exclusively at specific points of the communicating ducts. If it is desired to vary the proportion of the liquid-air in each tank, it is sufficient to vary the inclination of the apparatus from the vertical at the time of pouring the sample liquid.

It is noted that in relation to this date, the best method known to applicants to implement said invention is that which is clear from the present description of the invention.

Claims

1. - Apparatus for distributing liquids shown in small volumes, which comprises a rigid preformed duct of non-permeable material, with one inlet and one or more outlets, characterized in that the dimensions of the duct vary along it, forming communicating ducts, bifurcations and deposits.

2. - The apparatus for distributing liquids shows in small volumes according to claim

1, characterized in that each reservoir has inlet ducts that communicate it with the inlet duct of the sample liquid and / or with other reservoirs as well as outlet ducts that communicate it to other reservoirs and / or to an outlet duct.

3. - The apparatus for distributing liquids shows in small volumes according to claim 1, characterized in that two or more tanks are connected in series with each other by means of conduits.

4. - The apparatus for distributing liquids shows in small volumes according to claim 1, characterized in that the pipeline is located in such a way that the entrance and the exit (s) are at a higher level and below it are two or more deposits

5. The apparatus for distributing liquids shows in small volumes according to claim 1, characterized in that it is made of materials selected from polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyester, ethylene vinyl acetate (EVA), polyethylene (PE), polypropylene (PP) or similar, or a combination of them, thermoplastic or thermofix that meets the characteristics.

6. Use of the apparatus for distributing sample liquids in small volumes according to claim 1, characterized in that the sample liquid is poured into the upper part of the duct and due to the effects of gravity and air displacement, it is distributed in each of the smaller deposits through the communicating ducts, the liquid sample enters each smaller tank and remains at the bottom of it allowing the percentage of the determined air to remain within this by locating the exit ducts at the desired height. The excess air contained in these, as well as the rest of the liquid shows, exits through the communicating ducts at the entrance of another tank and finally through the outlet ducts that go up to the top allowing the desired distribution in each of the smaller deposits

7. - Process for manufacturing the apparatus for distributing liquid samples in small volumes according to claim 1, characterized in that it comprises: forming a thermoformed plate of polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyester, ethylene vinyl acetate (EVA), polyethylene (PE), polypropylene (PP) or similar, or a combination thereof, thermoplastic or thermofix that meets the characteristics, which includes the pipeline, and in turn communicating conduits, bifurcations and deposits, which is joined by heat and / or pressure medium and / or an adhesive to a complementary plate, being joined forming a rigid and impermeable duct, by means of a suction the contour is cut and the communicating conduits are opened to the outside.