p95-NBS1 Colorimetric Cell-Based ELISA Kit

A Cell-Based ELISA Kit from Assay Genie is designed to detect and quantify levels of p95/NBS1 protein in cell lysates and tissue samples. The assay uses a colorimetric detection method at 450 nm in a microplate format, with a dynamic range of > 5000 cells. Reactivity is specified for human samples, and the kit is intended for storage at 4°C with a stated stability of 6 months.

The format is described as a convenient, lysate-free, high-throughput and sensitive assay that detects the p95-NBS1 protein expression profile in cells. It can be used to measure relative amounts of p95/NBS1 in cultured cells and to screen for the effects of various treatments, inhibitors (such as siRNA or chemicals), or activators on p95/NBS1. Qualitative determination of p95-NBS1 is achieved by an indirect ELISA approach: p95-NBS1-specific primary antibodies capture the target, while HRP-conjugated secondary antibodies bind the Fc region of the primary antibody, allowing the conjugated HRP to catalyze a colorimetric reaction upon substrate addition. Because the assay is qualitative, a monoclonal antibody specific for human GAPDH is included to serve as an internal positive control for normalizing target absorbance values, and a Crystal Violet whole-cell staining step can be used to determine cell density so that absorbance values can be normalized to cell amounts.

The target, p95-NBS1, corresponds to the NBN gene (Gene ID 4683, UniProt ID O60934), which encodes nibrin, also known as cell cycle regulatory protein p95 or Nijmegen breakage syndrome protein 1, with a stated molecular weight of 84,959 Da. NBS1 is a member of the MRE11/RAD50 double-strand break repair complex and is involved in DNA double-strand break repair and DNA damage-induced checkpoint activation. Research applications include studies of DNA repair pathways and cellular responses to DNA damage, with relevance to genomic stability and cancer.