Human Cystatin B ELISA Kit

A sandwich Enzyme-Linked Immunosorbent Assay (sELISA) from Antibodies.com designed for the in vitro quantitative determination of human Cystatin-B in serum, plasma, tissue homogenates or other biological fluids. The kit employs the sandwich enzyme immunoassay technique using a microtiter plate pre-coated with an antibody specific for Cystatin-B. Standards and test samples are added to the wells, where Cystatin-B present in each sample is bound by the immobilized antibody. Following incubation and washing, a Biotinylated Anti-Cystatin-B Antibody binds the captured Cystatin-B, after which an HRP-Avidin conjugate is added. TMB substrate solution is then used to visualize the HRP enzymatic reaction, producing a blue-coloured product that changes to yellow upon addition of acidic stop solution. The density of yellow is proportional to the amount of Cystatin-B captured in each well, and the concentration is calculated by reading the O.D. absorbance at 450 nm in a microplate reader against a standard curve.

The assay has a sensitivity of <0.118 ng/ml and an assay range of 0.312–20 ng/ml, with a total assay time of 4 hours 30 minutes. Detection is colourimetric on a pre-coated microplate, and the kit is suitable for serum, plasma and tissue homogenates.

Recovery performance was assessed across sample types. Average recovery ranges were 80%–102% for serum (n=5), 81%–100% for EDTA plasma (n=5), and 80%–89% for Heparin plasma (n=5). Dilution linearity was evaluated at 1:2, 1:4, 1:8, and 1:16 across serum, EDTA plasma, and Heparin plasma (n=5 each). Kit components should be stored at +4°C or -20°C as instructed and the kit must not be used past its expiration date.