Stefin B Colorimetric Cell-Based ELISA Kit

From Assay Genie, this colorimetric cell-based ELISA kit enables the precise measurement of stefin B levels in cell lysates and tissue extracts. The assay is run in a 96-well microplate format and uses an indirect ELISA approach, in which stefin B is captured by stefin B-specific primary antibodies and detected with HRP-conjugated secondary antibodies that catalyze a colorimetric reaction upon substrate addition. Detection is read at 450 nm, and the dynamic range is greater than 5000 cells. The kit is reactive with human and rat samples and is suited to work with adherent cells.

Because the assay is lysate-free and high-throughput, it can be used to compare stefin B expression across cultured cells and to screen the effects of various treatments, inhibitors (such as siRNA or chemicals), or activators on stefin B levels. A monoclonal antibody specific for human GAPDH is included as an internal positive control for normalising target absorbance, and the Crystal Violet whole-cell staining method is provided for determining cell density, allowing absorbance values to be normalised to cell amounts to correct for plating differences.

Stefin B, also known as cysteine proteinase inhibitor, is an intracellular thiol proteinase inhibitor (UniProt ID P04080; gene symbol CSTB) that regulates protease activity and has been implicated in neurodegenerative disorders and cancer. The kit should be stored at 4°C, where it remains stable for 6 months.