Human Cystatin C ELISA Kit Instructions for Use

Human Cystatin C ELISA Kit

  ( for use in serum, plasma, cell culture supernatants, and urine biological fluids )

principle

This experiment used double antibody sandwich ABC-ELISA. Coated with anti-human Cystatin C monoclonal antibody on the microtiter plate, Cystatin C in the standard and sample was combined with monoclonal antibody, biotinylated anti-human Cystatin C was added to form an immune complex attached to the plate, horseradish Oxidase-labeled Streptavidin is combined with biotin, the substrate working solution is blue, and finally the stop solution sulfuric acid is added. The OD value is measured at 450 nm. The concentration of Cystatin C is directly proportional to the OD value. The specimen can be obtained by drawing a standard curve. Cystatin C concentration.

Kit composition ( 2-8 ° C preservation)

Prepare reagents and collect blood samples

1. Collection of specimens: serum, plasma (EDTA, citrate, heparin anticoagulation), cell culture supernatant, tissue homogenate, urine, etc., as soon as possible, stored at 2-8 ° C for 48 hours; longer time must be frozen ( -20 °C or -70 °C) Save to avoid repeated freezing and thawing. Urine, saliva, bronchial fluid, and cell culture supernatant were diluted 1:5. Serum and plasma were diluted 1:20 times.

2. Standard solution preparation: Add 0.3 ml of distilled water before use and mix to form a 400 ng/ml solution. Set 8 tubes of standard tubes, and add 300 ul of standard dilution solution to each tube. Add 400 ng of standard solution of 400 ng/ml to the first tube, mix and aspirate 300 ul with a sampler, and transfer to a second tube. Repeat the dilution in this way, and remove 300 ul from the seventh tube and discard it. The eighth tube is a blank control.

3. The 10× specimen dilution was diluted 1:10 with distilled water (example: 1 ml concentrated dilution + 9 ml distilled water).

4. Washing solution: diluted 1:20 with distilled water (example: 1 ml concentrated washing solution added to 19 ml of distilled water)

Test procedure

1. Loading: Add 100 ul of standard or sample to be tested in each well. Mix the reaction plate thoroughly and let it stand at 37 °C for 120 minutes.

2. Wash the plate: Wash the plate thoroughly with washing solution 4-6 times, and dry it on the filter paper.

3. Add 100 ul of the first antibody working solution to each well. The reaction plate was thoroughly mixed and placed at 37 ° C for 60 minutes.

4. Wash the board: the same as before.

5. Add 100 ul of enzyme-labeled antibody working solution per well. The reaction plate was placed at 37 ° C for 30 minutes.

6. Wash the board: same as before.

7. Add 100 ul of substrate working solution per well, set 37 The reaction was carried out in the dark at °C for 15 minutes.

8. Add 100 ul of stop solution to each well and mix.

9. Measure the absorbance at 450 nm using a microplate reader within 30 minutes.

Result calculation and judgment

1. All OD values ​​should be subtracted from the blank value before calculation.

2. Using standard products 200, 100, 50, 25, 12.5, 6.25, 3.12, 0 ng/ml as the abscissa and OD as the ordinate, plot on the coordinate paper and draw the standard curve.

3. Find the corresponding Cystatin C content on the graph based on the OD value of the sample, and multiply by the dilution factor.

Kit performance

1. Sensitivity: The minimum Cystatin C assay concentration is less than 1.5 ng/ml.

2. Specificity: Recombinant or natural human Cystatin C can be detected simultaneously. Does not cross-react with other human cytokines.

3. Repeatability: The coefficient of variation in the plate and plate is less than 10.6%.

Precautions

1. It is recommended to make double holes for the above standard holes and samples to be tested. The standard curve should be made at the same time for each measurement.

2. The washing process is critical. Insufficient washing will result in an accuracy error and an erroneous rise in the OD value.

3. After the slats are opened, the remaining slats should be sealed again to keep the slats dry .

4. This kit should be stored in a 4 ^o C refrigerator.

5. This kit is for scientific research only and cannot be used for clinical diagnosis!