DE29616373U1 - Test strips for analytical detection methods - Google Patents

Description

G 3530-03175/gh

Test strips for analytical detection methods

The present invention relates to a test strip for analytical, in particular diagnostic, detection methods, wherein the test strip carries one or more codes. The invention also relates to a test kit for such detection methods, which also contains, among other things, a test strip with antigen or antibody, where the test strip carries one or more different codes.

Nowadays, many diseases can be treated very effectively, provided that one can ensure that they are diagnosed in good time and correctly. There are therefore a whole range of diagnostics available that are designed to enable such a rapid and accurate diagnosis. Diagnostics can be divided into chemical, biochemical and immunological. Chemical diagnostics generally make use of colour reactions, which are often evaluated by colourometry, while biochemical diagnostics use enzyme reactions. Immunoelectrophoresis, radioimmunoassays and other immunochemical methods are examples of immunological diagnostics. A whole range of different rapid procedures are already available for the various diagnostics, with a test kit containing test papers, test sera and sticks in addition to the other necessary test components.

The daily routine of a clinic or a general practitioner includes examining several patients per day using the same diagnostic procedures,

as well as examining a patient with numerous different tests.

It often happens that a patient only has an indeterminate clinical picture, so that several diagnostic tests have to be used to make an accurate diagnosis for one and the same patient. If you take into account the workload in both clinics and in the practices of general practitioners, there is automatically a very high risk of confusion, especially if several patients have to be examined within a short period of time, for each of whom several diagnostic tests are carried out in parallel.

However, the diagnostic detection methods available on the market do not make it possible to distinguish between the various tests used during parallel operation in a laboratory. Rather, within a test kit, for example, several identical-looking test sticks are offered that have no way of distinguishing them from one another. Likewise, test sticks from different test kits can look identical to one another.

It is therefore an object of the present invention to mark a test strip in such a way that - in addition to its function as a detection reagent - it can be distinguished from other test strips which either carry a different patient sample or contain other reagents.

It was a further object of the invention to provide a test kit for diagnostic detection methods which, among other things, contains distinguishable test strips.

The above object is achieved by the subject matter of claim 1. According to claim 1, a test strip for diagnostic detection methods is provided, which is characterized in that it bears a code. This

Coding is preferably applied to one end of the test strip so that it does not interfere with the detection reaction on the test strip. Coding enables the doctor and/or the medical assistant or nurse to assign the respective test strip to a specific patient or to assign it to a specific test, for example if it is in a device together with other test strips.

In a preferred embodiment according to the present invention, the test strip contains a combination of two or more codes. In this way, the test strip can not only be assigned to a patient or not only to a specific test, but it can be assigned to a very specific test-patient combination. This enables each individual test strip to be assigned perfectly to an individual patient and the respective detection method. The risk of confusion is thus excluded, even in hectic operations in clinics or at general practitioners' offices.

In a further preferred embodiment, at least one of the selected codings is a color coding. Such a color coding can consist of a color strip attached to the end of the test strip, or it can be a color field that serves as a base for further coding.

Another preferred embodiment according to the invention provides that at least one of the codes is a barcode. Barcodes have the advantage that any number of data, for example from different patients or different detection methods, can be stored in them. This barcode can be provided in addition to the color coding or other codes. It can also be applied to a color field as described above. It has the advantage that several parameters can be stored simultaneously in one code.

Furthermore, according to a further preferred embodiment of the invention, at least one of the codes can be a number. Number codes have the advantage of being easy for everyone to recognize and thus a particularly secure assignment. In a further preferred embodiment, at least one code is a letter code, for which the same applies as for the number code. Both codes can be applied next to another code or, for example, arranged on a color field.

Finally, according to a further preferred embodiment of the invention, it can be provided that at least one coding is a symbol code. A symbol code is, for example, preferably appropriate for the simple and reliable assignment of test strips to specific detection methods.

It is particularly preferred that a test strip that has more than one code should have at least two different codes. This combination of different codes ensures that, in addition to avoiding the risk of confusion, it is made clear which code is responsible for the different patients and which code is responsible for the different detection methods.

In a particularly preferred embodiment according to the present invention, the test strip contains two codes, one code being a numerical code and the other code being a colour code. In this embodiment, the number can code for different patients, while the colour code can code for different detection methods. The colour code can be applied as a colour field at the end of a test strip. The colour field can then additionally contain the numerical code. This type of marking also takes up little space on the test strip, which is preferable because the coding does not affect possible test reactions of the test when carrying out the analyses.

It is particularly preferable that the codes on the test strips are machine-readable. This allows automation and thus also increases the speed of the tests. Machine-readable codes can be, for example, barcodes or color codes that can be analyzed, i.e. recognized, using spectrometric analysis. Such machine-readable codes have the additional advantage that they make the process cheaper overall through automation. The further risk of confusion due to human error can be almost completely ruled out in this case.

It was a further object of the present invention to provide a test kit for diagnostic detection methods, which reduces the risk of confusion.

This object is achieved by the test kit for diagnostic detection methods specified in claim 12. Preferably, it is a test kit for carrying out immunochemical analyses.

Such a test kit, which contains a test strip with one or more different codes, enables a clear assignment to a specific patient and to a specific diagnostic detection method. This eliminates confusion even in the hectic life of a clinic or practice. These double codes therefore enable a test strip to be clearly assigned to two parameters, such as the patient and the type of test.

The test strip for diagnostic detection methods mentioned here can, for example, be both a test paper and a test stick, but should not be limited to these examples.

The diagnostic detection methods can be all of the above-mentioned possible diagnostic detection methods, in particular the test strip according to the present invention can be used for

immunological, diagnostic detection methods based on an antigen-antibody reaction can be used. Of course, the test strips according to the invention can also be used in methods that are not exclusively used to determine a diagnosis, but also in methods that only aim to analyse a sample without the analysis result forming the basis for a diagnosis.

In the following, the invention will be explained in more detail using some examples.

Examples

Example 1) Western blot test kit for the detection of specific IgG or IgM antibodies against parvovirus B19.

The Western blot test kit contains the following reagents:

20 nitrocellulose strips with capsid antigen of parvovirus B19, ready to use, each nitrocellulose strip has a green color marking on one end as a color field, indicating that it is to be used to detect specific IgG or IgM antibodies against parvovirus B19. Numbers from 1-20 are printed in the color field.

250 μl Parvovirus B19 IgG or IgM positive control, human lyophilized (Parvovirus B19 Positive Control WB).

250 μηδ Parvovirus B19 negative control, human, lyophilized (Parvovirus B19 negative control WB).

4.5 ml goat antihuman globulin IgG conjugate conjugated with alkaline phosphatase, lyophilized.

IgG specific for IgG kit (10 A.P. Conj.), (Anti-Hu IgG) IgM specific for IgM kit (10 x A.P. Conj., Anti-Hu IgM).

45 ml Chromogen/Substrate solution, ready to use 100 ml Sample/Wash buffer solution, 10x concentrate 1 pack Sample/Wash buffer salt

To carry out the diagnostic test, the lyophilized reagents are reconstituted at least 15 minutes before use and mixed carefully to avoid foaming. For reconstitution and dilution, only pure distilled water at room temperature should be used.

The sample wash buffer solution is diluted in distilled water (100 ml concentrate plus 900 ml distilled water); then the sample wash buffer salt is added completely and mixed well until all the salts are dissolved. It may be necessary to place the mixture on the magnetic stirrer for 10 to 15 minutes at pH = 7.5 +/-0.1.

The conjugate lyophilisate is dissolved in 4.5 ml distilled water. The concentrate is diluted 1:10 with sample wash buffer diluent. The remaining reagents are ready for use. 20 μl of undiluted patient serum are used as patient samples per test. Before the actual test, all test components and samples should be brought to room temperature and carefully mixed by shaking 4 to 5 times.

First, shortly before use, the incubation trays are rinsed briefly with coarse wash buffer to remove dust particles. It is not necessary to label the incubation trays on the back, as the test strips already have a code that prevents confusion. This is particularly

advantageous because the labelling of the rear incubation trays can be forgotten at first, or if it is not forgotten, it causes problems because one has to lift the tray to read the labelling on the rear and in doing so could damage or interfere with the tests.

For each control and patient sample, an antigen strip is now taken with Teflon or plastic tweezers, with the side bearing the code facing up so that the code can be read. The antigen is preferably bound to this side.

The antigen strip is placed in a groove in each of the incubation trays. The antigen strip is then completely wetted with 2 ml of sample wash buffer. The incubation tray is placed on a shaker with a cycle frequency of approximately 40 per minute, ensuring that overflow is avoided. Then 80 μl of the control working dilution and 20 μl of the patient sample are added. This should be done while the shaker is running. For the IgG test, incubate on the shaker for 30 minutes at room temperature, for the IgM test, incubate on the shaker for 45 minutes at room temperature. The liquid is then poured off and the remaining liquid is tapped off onto filter paper.

The antigen strip is then washed 3x5 minutes. To do this, 2 ml of washing buffer is added each time, incubated for 5 minutes at room temperature and then the liquid is poured off. Now 2 ml of fresh conjugate working dilution is added by pipette; it is again incubated on the shaker for 15 minutes. The conjugate is then poured off. This is followed by washing 3 times as above. Then 2 ml of distilled water is added each time and incubated on the shaker for 1 minute at room temperature. The liquid is again poured off and then 2 ml of chromogen substrate solution is added by pipette. This solution is allowed to develop on the shaker for 4-12 minutes

or until the 140 kD band is clearly visible in the IgG positive control, or until a 140 kD band is just visible in the weakly positive IgM control. At the same time, the IgM positive control should be clearly executable.

The reaction is stopped by pouring off the liquid. Without intermediate incubation, rinse 3 times with 2 ml distilled water each time. The strip is then dried and evaluated.

Evaluation for IqG Marblot:

If no band appears at 140 kD, this means that the test was negative, i.e. no IgG antibodies against parvovirus B19 are detectable.

If a band is found at 140 kD, this means that the test is positive. IgG antibodies against parvovirus B19 are detectable.

Evaluation for IqM-Marblot:

If no band is detectable or if it is weaker than the kD band of the cut-off control, this means that the test was negative, i.e. no IgM antibodies against parvovirus B19 are detectable.

If the band at 140 kD is as strong or stronger than the cut-off control, this means that the test is positive

··· &idiag;♦♦··

LO

has failed, i.e. IgM antibodies against parvovirus B19 are detectable.

The coding at the end of the test strip means there can be no doubt as to whether it was a Parvovirus Big test or which patient the test was assigned to. This eliminates any risk of confusion between different detection methods or between different patients.

Example 2:

Treponema pallidum IgM Marblot test kit

This Western blot test kit is used to detect IgM specific antigen bodies against Treponema pallidum.

The kit has the following components:

20 antigen strips, nitrocellulose strips to which EBV antigens are bound, electrophoretically separated into individual bands, ready to use, (EBV Marblot Membrane Strips). Each strip has a red color marking at the end, which identifies it as a test strip for Treponema pallidum. Numbers from 1-20 are printed in the color field.

250 μεδ EBV IgG or IgM positive control, human, lyophilized, (EBV ... Positive Control WB)

250 μεδ EBV negative control, human, lyophilized, (EBV Negative Control WB)

4.5 ml goat antihuman globulin conjugate conjugated with alkaline phosphatase, lyophilized.

·♦

IgG specific for IgG kit (10 x A.P. Conj., Anti Hu

IgG)

IgM specific for IgM kit (10 x A.P. Conj., Anti Hu

IgM)

100 ml Sample Wash Buffer, 10x Concentrate, (10 x Sample Diluent)

1 pack of sample/wash buffer salt (Sample Diluent/Wash Powder)

45 ml Chromogen/Substrate Solution, ready to use, (Alkaline Phosphatase Developing Solution)

Patient samples are prepared by diluting 20 μl of a patient group with 2 ml of Diluent Wash Powder (1:100). The control working diluent is prepared by diluting 80 μl of control concentrate with 2 ml of Diluent Wash Buffer (1:25). The other reagents are prepared as follows. Lyophilized reagents should be constituted at least 15 min before use and mixed gently to avoid foaming.

For the control concentrate, lyophilized control is prepared with 250 μl of distilled water. For the conjugate concentrate, lyophilized conjugate is prepared with 4.5 ml of distilled water. For the conjugate consumption dilution, the conjugate concentrate is mixed 1:10 with dilution wash buffer shortly before use. 2 ml of diluted conjugate are required per sample (200 μl concentrate + 1800 μl dilution wash buffer). Dilute dilution wash buffer concentrate in distilled water 1:10 (100 ml concentrate + 900 ml distilled water; then add buffer salt and mix well. pH = 7.5 +/-0.1. Approx. 30 ml of ready-to-use buffer are required per sample.

■ ·

Working instructions; EBV Marblot

Before starting the test, bring all test components and samples to room temperature (20 - 25 ⁰ C) and mix gently by swirling 5 times.

Before use, rinse the incubation trays briefly with sample/wash buffer 1 x to remove dust particles. It is not necessary to label the incubation trays on the back, as the test strips already have a code that prevents confusion. This is particularly advantageous because the label on the back of the incubation trays can be forgotten at first, or even if it is not forgotten, it leads to problems because the tray has to be lifted to read the label on the back, which could damage or interfere with the tests.

For each control and patient sample, one antigen strip is placed into the tray using Teflon or plastic tweezers. The side with the color marking and number must be on top - the antigen is also bound to this side.

2 ml of sample/wash buffer are added and pre-incubated for 5 minutes at RT. Place on a shaker with a cycle frequency of at least 4 0/minute, avoiding overflow. The buffer should not be poured off.

Now add 8 0 μl of the control dilution or 20 μl of patient sample. Make sure that the shaker is running and that the incubation tray is swirled after each addition of serum. If possible, use a strip from the middle of the positive control (e.g. strips numbered 8 to 12).

For IgG: Incubate for 30 minutes at RT on the shaker For IgM: Incubate for 45 minutes at RT on the shaker

The liquid is poured off and the remaining liquid is tapped onto filter paper.

The antigen strip is then washed 3x5 minutes. To do this, 2 ml of washing buffer is added, incubated for 5 minutes at room temperature and then the liquid is poured off. Now 2 ml of fresh conjugate working dilution is added by pipette; it is again incubated on the shaker for 15 minutes. The conjugate is then poured off. This is followed by 3 more washes as above. Then 2 ml of distilled water is added and incubated on the shaker for 1 minute at room temperature. The liquid is poured off again and then 2 ml of chromogen substrate solution is added by pipette. This solution is allowed to develop on the shaker for 4-12 minutes or until the 140 kD band is clearly visible in the IgG positive control or until a 140 kD band is just visible in the weakly positive IgM control. At the same time, the IgM positive control should be clearly executable, or until at least specific bands of the positive control are recognizable, or until at least 3 specific bands of the positive control are recognizable.

The reaction is stopped by pouring off the liquid.

Rinse 3 times with 2 ml of distilled water each time.

Finally, the strips are dried and evaluated.

The risk of confusion is excluded, as the test strips contain both a code for the respective patient

as well as a code for the specific diagnostic detection method.

Claims (12)

15 Protection claims 1. Test strip for analytical and/or diagnostic detection methods, characterized in that the test strip carries at least one code. 2. Test strip according to claim 1, characterized in that the test strip carries a combination of two or more codes. 3. Test strip according to claim 1 or 2, characterized in that at least one coding is a color coding. 4. Test strip according to claim 1 or 2, characterized in that at least one coding is a bar coding. 5. Test strip according to claim 1 or 2, characterized in that at least one coding is a number code. 6. Test strip according to claim 1 or 2, characterized in _that at least one coding is a letter code. 7. Test strip according to claim 1 or 2, characterized in that at least one coding is a symbol code. 8. Test strip according to claim 2, characterized in that the codes are at least two different codes according to claims 3 to 7. 9. Test strip according to claim 8, characterized in that the strip contains two codes, one code being a numerical code and the other code being a color code. 10. Test strip according to claim 9, characterized in that the numerical code encodes different patients and that the color code encodes different tests. 11. Test strip according to one or more of the preceding claims, characterized in that the codes are machine-readable. 12. Test kit for an analytical and/or diagnostic detection method, comprising at least a test strip according to any one of claims 1-11 and a further means for carrying out the test.