DE3226407A1 - Microanalysis capillary system - Google Patents

Abstract

The microanalysis capillary system is a micro test system for qualitative and quantitative tests of liquids and particulate constituents thereof, especially of body fluids in the fields of science and medicine. It is based on a transparent, sterile capillary tube which fills automatically through capillarity and has an inner wall coated with reagent, a defined volume and flat bottom and top surfaces the depth of which is chosen in such a way that differentiation of individual particles of the material being tested is possible, if required (monocellular layer). Multiple tests can be carried out by parallel arrangement of several capillary tubes provided with a common detachable inlet which breaks off when the front and rear caps of the protective covering are compressed. The preparation and the analysis take place after removal of the sample, for example by means of an upstream puncturing cannula in the capillary tube which represents a sterile enclosed system after cementing of the ends as a protection against external influences, which system is surrounded by a protective cover which can be written on. Analysis is predominantly via optical, microscopic and photometric methods and via methods of fluorescence technology.

Description

The invention relates to a micro test system according to

the preamble of claim 1. The microtest system is intended to carry out before various test procedures in the natural sciences and medicine, in particular to k 1 i n i s ch- cii em i s c 10 em, i mmu n o 1 0 g i s che em haematological and microbiological area in the clinic, in the practice as well simplify and improve in scientific laboratories.

Conventional scientific-medical procedures for qualitative and quantitative investigations of body fluids. i.a.

described in RICK, Klinische Chemie und Mikoskopie, 1977, Springer Verlag, ISBN 3-540-08219-05, as well as L. THOMAS, Labor und Diagnose, 1978, Medizinische Verlagsgesellschaft Marburg, ISBN 3-921320-10-8, are generally extremely personal and non-material intensive. From the acquisition of the test material 5 to the evaluation of the approach are usually a number of more time-consuming and complicated, with considerable Infection risk of associated operations is necessary. A large part of these investigations requires aseptic or at least low-germ work. Contamination is coming often occurs in conventional systems. Conventional examinations require in Usually significant amounts of test material and are associated with physical and psychological stress on the patient (especially of intensive care patients and children Etc.). The applicability of today's test systems is mostly to special areas limited. The increased expenditure on equipment associated therewith brings extremely high costs Costs with itself. Due to a large number of intermediate steps and manipulations Conventional test methods are very susceptible to interference. Standardization is made more difficult at the expense of precision. Especially with se clii quantitative examination methods (e.g. test strips) is an increase in precision with today's state of the art Exact dosage of the test material only with elaborate methods (micropipette) possible with considerable expenditure of time.

The high material and personnel costs for the specialized and thereby partly allctl more prone to failure, extravagant and complicated, conventional Test systems entail high costs. In addition, there is a risk of the Staff when handling infectious test material or toxic reagents.

The patients are mostly psychological and physical by nature and extent taking the samples, e.g.

Blood samples, contaminated, as some methods require an unnecessarily large amount of test material require.

The MTS has the task of establishing known test procedures for qualitative and quantitative analysis of liquids or solid components of these liquids (especially body fluids) to optimize and economize, whereby a Reduction of personnel and material costs, work processes, susceptibility to failure, the endangerment of the staff as well as the stress on the patient is to be achieved. In addition, the MTS should be easy to use and speed up the availability of results. With the introduction of the MTS, a considerable Cost reduction in areas where more complex processes are currently used, can be achieved. The capacity and efficiency of laboratories could be increased significantly will.

According to the invention, these objects are achieved by an MTS as claimed 1-12 solved. The advantages of this invention over conventional technologies are considerable savings in personnel and material costs (rtmicro approach), almost universal Applicability (depending on capillary coating), increase in storage capacity and storage time (sterile, with all, partly

micro-batches provided with lyophilized test reagents). The almost The universal applicability of the MTS limits the amount of equipment that has been customary up to now considerably a.

Additional devices for evaluating the approach are not essential necessary. However, the efficiency can be achieved through a machine evaluation of the system can be increased many times over. Be quantitative studies like they are common with test strips can be done using the same methods with can be carried out more precisely with the MTS, as the F! TS guarantees a standardized volume and, moreover, the susceptibility to failure due to reactions in the closed system is decreased. By photometric evaluation of the approach, an increased Precision of this investigation can be achieved. It is also important that the test results are available more quickly. The approach is largely insensitive to interference (Germs etc.). The MTS is easy to handle. The compactness of the MTS as well as its sterile sealability enable a complication-free Dispatch of the immediately available approach. Only minimal amounts are required for the approach Quantities of test material required. Together with the gentler extraction of the Material, this reduces the stress on the patient. Because the MTS after puttying represents a closed system, any risk of infection is excluded. The risk of contamination is also extremely low. The elimination of the sample is possible in an environmentally friendly way.

The MTS is widely used in scientific and medical fields Use for qualitative and quantitative analyzes, especially for medical ones Diagnostics and therapy control, especially for examinations of body fluids, such as blood, urine, liquor, saliva, amniotic fluid, sweat, stomach acid, glandular secretions, Bile, semen, vesicle contents, sputum, wound secretions, effusions and abscesses. the many advantages of the MTS make the systefil suitable for all units of the medical Supply, d. H.

Interesting for both practice and large-scale laboratories therefore expect great demand.

The capillary is formed from a transparent lower part (1), consisting of a thin plastic or glass plate into which a e.g. 50-100 mm long, 1.0 mm wide and 0.010 nii deep tub incorporated (embossed, rolled, etched, etc.) is. The bottom surface of the tub must be flat and with that for the respective Reagent coating (2) required for the test batch. The lower part (A) is provided with a transparent cover layer (3) and so with the Lower part connected that the tub is covered and lengthways on both sides is tightly closed. This connection (4) can be made, for example, by gluing. The result is a capillary lumen (5), e.g. with the dimensions 0.010 mm x 1.0 mln x 100 mm, which is only open on the front and back. Functionally represents the part described so far is a capillary, which differs from the round shape differs in that the bottom and top surfaces are flat and therefore uniform Refraction is guaranteed so that the capillary contents can be viewed with your microscope can be. The dimensions mentioned are suitable when examining blood samples to reveal a monocellular layer microscopically. This form is therefore suitable for most of the following application examples.

For stabilization, to facilitate handling and as protection The MTS is provided with a cover to protect it from dirt and damage.

This consists of a transparent block (6) containing several in surrounds combined MTSs (7) with different coatings, arranged on one level, the area above the measuring chamber (8), which is the evaluable area of the capillary represents, but leaves free, so that the objective of the microscope directly to the Top layer can be brought up.

A common filling part is connected upstream of the combined capillaries (7). This consists of a puncture cannula (9) and a common inlet (10), which is attached to the block (6) in such a way that it passes through when the MTS is closed the front cap (12) breaks off at the predetermined breaking point (11). The common filling part is activated when pushing the caps together (closing process) by pressing the, as Steel insert (15) formed in an inclined plane in the front cap (12) of the block (6) canceled. During the sealing process, the capillary ends are putty (14) located in the front and rear cap (12, 13), closed.

A removable middle part (16) protects the MTS up to the filling. After filling, this is removed. The protective function is activated after locking taken over by the front and rear cap (12, 13) completely surrounding the block. Before the MTS is closed, the middle part (16) is secured with its locking mechanism (17) fixed in the locking mechanism (19) of the rear cap. The locking mechanism (21) at the rear of the block prevents the rear cap from sliding back (13) beyond the end of the block. The locking mechanism (20) on the front part of the Blocks prevents the front cap (12) from being pushed back over the front block. When unlocked, the middle part (16) prevents pushing the two caps (12, 13) together. The front cap is put on so that it does not protrude beyond the anterior snap-in mechanism (20) and towards the filling of the MTS can be removed. After filling the MTS will be after the tundra part (16) has been removed, both caps (12, 13) pushed against each other and over their locking mechanisms (18, 19) connected to one another.

This connection can be used for evaluation by lightly adding to both Caps are loosened again, with the front cap (12) on the locking mechanism (20) of the front part of the block, the rear cap (13) on the locking mechanism (21) of the Block rear part is locked. The view is then in the re-opened state released on the measuring chamber (8). At the end of the rear cap (13) is a fastening clip (22) attached, which fixes the MTS to the smock pocket or to the microscope stage enables.

Sampling: The liquids to be examined are taken using conventional methods.

Frequent decanting is avoided by taking it directly subsequent filling of the MTS.

Blood samples can be obtained by direct venipuncture through a deiii tlTS coupled, thin cannula or by taking blood from fingers or Ear lobes can be obtained sterile using a lancet. By capillarity becomes the sample is then taken from the cannula or, if necessary, when it is removed using a lancet after discarding approx. 4 drops of blood (standardization) into the MTS.

Approach: The reagents necessary for the reaction, the s i c ti as a coating on the inside of the capillary (e.g. pulverized, lyophilized, etc.) are dissolved by the liquid test material (diffusion). The necessary reagents can be staggered in time for introductory or teaching phase tests be released from their microencapsulation. After a short time a Set the reagents to be evenly distributed. Must for blood tests the MTS may also be coated with anticoagulants.

Evaluation: A large part of the approaches is then through color reactions, e.g. selective enrichment of dyes, color changes (color change), color intensity, Color differentiation by two or more colors, either with the naked eye, evaluated microscopically or by machine. Further evaluation principles are based on morphological criteria, scattered light measurement, extinction, etc.

The variety of the individual test procedures that can be carried out with the MTS does not permit a comprehensive presentation at this point. Common uses are briefly explained below.

For part of the blood tests with the aim of cell differentiation the MTS replaces the conventional blood smear.

Leukocyte count: A capillary coated with acridine orange is filled with blood.

Acridine orange combines with deoxyribonucleic acid (DNA) of the vital nucleated blood cells (leukocytes), which is imniunfluoreszenzoptisch Excitation in the blue area as green fluorescence of the nuclei is impressive and visible to the eye can be seen microscopically under sufficient magnification. Counting the cells is made possible in this way. The determined number of cells allows for a defined volume of the Counting chamber draws a conclusion about the leukocyte concentration in the blood. It offers A machine evaluation by measuring the light intensity can also be used. One Staining with conventional reagents (PAPPENHEIM) also allows evaluation with the light microscope.

Erythrocyte count: In the same sample can be with little effort also other blood cells, especially erythrocytes, based on morphological criteria and / or count by staining (YEFl).

Determination of hematocrit and hemoglobin: By centrifuging the MTS a cell-plasma separation can then be achieved for the hematocrit determination can be recovered. The hemoglobin content is determined in the same Sample photospectrometrically. Variables such as the mean corpuscular hemoglobin concentration (HbE, MCH), the mean Hb concentration (MCHC) and calculate the mean corpuscular volume (MCV).

Platelet count: Platelets are determined by staining with thioflavin or primulin.

In the immunological field, there are three principles of, among others Meaning: surface antigen labeling with fluorescent dye-conjugated antibodies, Cytotoxicity test (HLA typing, HLA-B 27 determination) and agglutination reaction (Blood group determination).

The first method is based on the attachment of (monoclonal) antibodies, e.g. on surface antigen structures of blood cells. The second method is based on lysis t evoked by immune complex binding in conjunction with complement. the lysed cells (positive reaction) are presented with a dye (e.g.

Ethydium bromide, propidium iodide) (red with blue excitation). That The latter method is based on opsonization of the cells (erythrocytes) with antibodies with subsequent agglutination of the cells (blood group determination).

In these approaches, too, the reagents are lyophilized Form applied to the inner wall of the capillary.

The examination of bacteria (e.g. in urine) can also be done with the MTS are done by adding a suitable culture medium to a capillary inner surface is coated. After a certain time, depending on the design of the capillary the quantification of the approach by counting the microscopic or macroscopic recognizable bacterial colonies that emerge after a while from individual bacteria have formed on the culture medium. The differentiation of the bacteria can, among other things, by Selective culture media or via fluorescent dye conjugated (monoclonal) antibodies take place. As a supplement to diesel examinations, an antibiogram can be performed immediately, e.g. with antibiotic-coated capillaries or microencapsulated Antiobiotics are created in conjunction with microencapsulated dyes. A Comparison of the first approach with the negative control (antibiotic-free) permitted a statement about the sensitivity of the bacteria to the examined antibiotic.

Clinical-chemical investigations of soluble substances in (body) Liquids (e.g.

Glucose, enzymes, hormones, etc.), so far mainly photometric in a cuvette can be made with the MTS using much smaller Sample quantities, possibly after centrifugation, can be carried out more easily.

This is especially true for processes that are currently semiquantitative can be carried out with test strips. Some of the approaches can result in color reactions can also be read by eye (e.g. urine pH with the indicator phenolphthalein and litmus, urine protein using the biuret method).

L e r s e i t e

Claims (12)

PATENT CLAIMS 1 micro-analysis capillary system: micro test system MTS) for qualitative and quantitative analysis of liquids, especially body fluids, e.g. on the hematological, immunological, microbiological and clinical-chemical Area characterized by a reagent-coated, transparent, sterile capillary with a flat bottom and top surface and a rectangular cross-section, as well as a defined volume, which can be sealed at the ends with putty. 2. MTS according to claim 1, characterized in that the height of the serving as a measuring chamber capillary section in examinations of corpuscular Components of liquids (e.g. cell suspensions) is chosen so that the Particles to be analyzed can be differentiated individually (monocellular layer). 3. MTS according to claim 1 and 2, characterized in that reagents for multiphase ests can be applied to the inner wall of the capillary in a microencapsulated form. 4. MTS according to claim 1, characterized by a bottom of the capillary located standardized grid for microscopic evaluation, as well as microscopically recognizable Marking to identify the capillary coating. 5, MTS according to claim 1, characterized by an optical into the MTS integrated system (convex cut) with magnifying effect for macroscopic Evaluation. 6. MTS according to claim 1 and 5, characterized by a capillary width of over 0.1 mm, which allows a statement to be made about the filling status of the MTS. 7. MTS according to claim 1, characterized by a protective cover with labeling option and fastening clip ip. 8. MTS according to claim 1, characterized by an upstream puncture cannula (9). 9. Combination of several tiTSs according to claim 1, characterized by Combination of several different reagent-coated MTSs into one compact unit. 10. t4TSs according to claim 1, 8 and 9, characterized by a common separable inlet (10). 11. MTSs according to claim 1, 7, 8, 9 and 10, characterized in that that when closing the MTS by pushing the front (12) and rear (13) Cap of the protective cover of the common inlet (10) together with the upstream Puncture cannula (9) by applying pressure to an inclined plane (wedge-shaped) Steel insert (15) breaks off and at the same time the capillary ends with putty (14) the two poles of the protective cap. 12. MTS according to claim 1 and 9, characterized by processing of large-area reagent-coated plastic or glass foils or -plates into which the trough-shaped basic shape of the capillary is embossed, Rolling, etching, etc. is incorporated; the cover layer is preferably glued on.