What do you know about characterization and quantification in ELISA kits? -Huaqiang Electronic Network

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EL-C1600N100013-B

Elisa kit

Medium: Qualitative analysis and quantitative analysis should be unified and complementary; qualitative analysis is the basic premise of quantitative analysis. Unqualified quantitative is a blind and worthless quantitative; quantitative analysis makes it more scientific. Accurate, it can lead to broad and in-depth conclusions from qualitative analysis:

(1) Qualitative kit is to determine the presence or absence of a substance in a certain sample, generally expressed as negative or positive, specifically determined by the OD value, and the specific concentration of the substance cannot be calculated. A general qualitative kit will only come with a negative standard and a positive standard.

(2) Quantitative kit is used to determine the specific concentration value of a substance in a certain sample, generally in units, such as ng/ml. This kit is mainly used to determine the substance. Specific changes, such as increased or decreased, increased, reduced, and so on. It is generally determined that the sample contains the substance when a quantitative kit is used.

Shanghai win-win

Biotechnology Co., Ltd. ELISA test kit technology principle

:

(1). Solid phase of antigen or antibody and enzymatic labeling of antigen or antibody.

(2) The antigen or antibody bound to the surface of the solid support still retains its immunological activity.

(3). The enzyme-labeled antigen or antibody retains both its immunological activity and the activity of the enzyme.

(4) The test specimen reacts with an antigen or antibody on the surface of the solid phase carrier. Further, an enzyme-labeled antigen or antibody is added, and is also bound to the solid phase carrier by a reaction.

(5). At this time, the amount of enzyme on the solid phase is proportional to the amount of the substance to be tested in the specimen.

(6) After adding the substrate of the enzyme reaction, the substrate is catalyzed by the enzyme to become a colored product, and the amount of the product is directly related to the amount of the substance to be tested in the sample, so that qualitative or quantitative analysis can be performed according to the depth of the color. The assay has high sensitivity (pg-ng/ml level) and good repeatability. A highly sensitive test technique based on immunological reactions that combines the specific reaction of antigens and antibodies with the efficient catalysis of enzymes on substrates.

Shanghai Win-win Biotechnology Co., Ltd.

Sample preparation for ELISA

There must be a complete plan before collecting the sample, and it must be clear whether the ingredients to be tested are sufficiently stable. Samples that were tested on the day after collection were stored in time at 4 °C for later use. For samples that are retested every other day, they should be stored at -20 °C in a timely manner after sub-packaging. If conditions permit, it is best to freeze at -70 °C for later use. Specimens should avoid repeated freezing and thawing.

Liquid specimens: including serum, plasma, urine, pleural and ascites, cerebrospinal fluid, cell culture supernatant, etc.

1. Serum:

The blood is naturally solidified at room temperature for 10-20 minutes, and then centrifuged for about 20 minutes (2000-3000 rpm). Collect the supernatant carefully. If a precipitate forms during storage, it should be centrifuged again.

2. Plasma:

EDTA, sodium citrate or heparin should be selected as an anticoagulant according to the requirements of the specimen. After mixing for 10-20 minutes, centrifuge for about 20 minutes (2000-3000 rpm). Collect the supernatant carefully. If a precipitate forms during storage, it should be centrifuged again.

3. Urine:

Collect with a sterile tube. Centrifuge for about 20 minutes (2000-3000 rpm). Collect the supernatant carefully. If a precipitate forms during storage, it should be centrifuged again. The chest and ascites and cerebrospinal fluid are implemented with reference to this.

4. Cell culture supernatant:

When detecting secreted components, collect them in a sterile tube. Centrifuge for about 20 minutes (2000-3000 rpm). Collect the supernatant carefully.

5. Culture the cells:

When the components in the cells were detected, the cell suspension was diluted with PBS (pH 7.2-7.4), and the cell concentration reached about 1 million/ml. By repeatedly freezing and thawing or adding tissue protein extraction reagents, the cells are destroyed and the intracellular components are released. Centrifuge for about 20 minutes (2000-3000 rpm). Collect the supernatant carefully. If a precipitate forms during storage, it should be centrifuged again.

6. Organize specimens:

After cutting the specimen, weigh the weight. Add a certain amount of PBS, pH 7.4. It was quickly frozen and stored in liquid nitrogen for use. The specimen still maintains a temperature of 2-8 ° C after melting. Add a certain amount of PBS (pH 7.4), or tissue protein extraction reagent, and homogenize the specimen by hand or homogenizer. Centrifuge for about 20 minutes (2000-3000 rpm). Collect the supernatant carefully. One part of the package is to be tested, and the rest is frozen for use.