The Leukocyte Elastase Inhibitor （LEI，SERPINB1） BioAssay ELISA Kit （Human） is a quantitative sandwich assay for the detection of LEI in human serum，plasma，tissue homogenates and other biological fluids.Detection Range：0.312-20ng/mlSensitivity：<0.188ng/mlAssay Principle：The microtiter plate provided in this kit has been pre-coated with an antibody specific to LEI . Standards and samples are added to the appropriate microtiter plate wells followed by a biotin-conjugated antibody specific to LEI. Streptavidin conjugated to Horseradish Peroxidase （HRP） is added to each microplate well and incubated. After TMB substrate solution is added，only those wells that contain LEI，Biotin-conjugated antibody and enzyme-conjugated Streptavidin complex will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of sulfuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450nm ± 10nm. The concentration of LEI in the sample is then determined by comparing the O.D. of the sample to the standard curve.Kit Components：*358799A： Microtiter Strips，8x12 wells.*358799B： Standard，2 vials358799C： Sample/Standard Dilution Buffer，1x20ml358799D： Antibody-Biotin （Concentrated），1x120ul358799E： Antibody Dilution Buffer，1x10ml358799F： Streptavidin-HRP Conjugate （SABC），1x120ul358799G： SABC Dilution Buffer，1x10ml358799H： TMB Substrate，1x10ml358799J： Stop Solution，1x10ml358799K： Wash Buffer （25X），1x30mlStorage and Stability：Store unopened *358799A at 4ºC; store at -20ºC once opened. Store unopened *358799B at 4°C; once reconstituted store at 4°C for up to 12 hours or at -20°C for up to 48 hours. Store other components at 4°C. Kit is stable for 6 months after receipt. For maximum recovery of product，centrifuge the original vials after thawing and prior to removing the cap.Assay Summary：1. Wash plate 2 times before adding standards，samples and control （zero） to wells!2. Add 100ul standard or sample to each well and incubate for 90 minutes at 37°C3. Add 100ul Antibody-Biotin working solution to each well and incubate for 60 minutes at 37°C4. Aspirate and wash 3 times.5. Add 100ul SABC working solution to each well. Incubate for 30 minutes at 37°C6. Aspirate and wash 5 times.7. Add 90ul TMB substrate. Incubate 15-30 minutes at 37°C8. Add 50ul Stop Solution. Read at 450nm immediately.9. Calculate results.
