Human Calpain Small Subunit 1 ELISA Kit (A87008) employs the sandwich enzyme immunoassay technique for the quantitative measurement of human Calpain Small Subunit 1 in serum, plasma, tissue homogenates, and other biological fluids. An antibody specific for Calpain Small Subunit 1 has been pre-coated onto a 96-well microtiter plate. The standards and test samples are added into the wells and the Calpain Small Subunit 1 present in each sample is bound to the wells by the immobilized antibody. Following incubation, the wells are washed and then incubated with Biotinylated Anti-Calpain Small Subunit 1 Antibody, which binds the captured Calpain Small Subunit 1 present in each well. Following incubation, unbound biotinylated detection antibody is removed by washing, and an HRP-Streptavidin conjugate is added to the wells and the microtiter plate is incubated. Following incubation and washing, TMB substrate solution is then used to visualize the HRP enzymatic reaction by catalysis to produce a blue-coloured product that changes to yellow after addition of acidic stop solution. The density of yellow is proportional to the amount of Calpain Small Subunit 1 captured in each well. The concentration of Calpain Small Subunit 1 can then be calculated by reading the O.D. absorbance at 450nm in a microplate reader and referring to the standard curve.