Anti-RB1 (phospho S795) Antibody

A polyclonal rabbit IgG reagent from Antibodies.com that detects the retinoblastoma tumor suppressor protein (RB1) only when phosphorylated at serine 795. The antibody was raised against a synthetic phosphopeptide corresponding to residues flanking S795 of human RB1 and was affinity-purified against the phosphorylated epitope, allowing it to discriminate the CDK4/cyclin D- and CDK2/cyclin E-modified form from unmodified RB1 in cell lysates. Phosphorylation at S795 is a well-established biochemical readout of G1/S checkpoint progression: the modification disrupts RB1 binding to E2F transcription factors, releasing them to drive S-phase gene expression, and is widely used in oncology and cell biology studies to monitor cyclin-dependent kinase pathway activity, tumor suppressor inactivation, and proliferative signaling.

Supplied as a 50 µl aliquot of unconjugated antibody, the reagent is validated for Western blot detection of the modified protein in human samples. On blots, the antibody recognizes the endogenous ~106 kDa RB1 band in lysates prepared from cultured human cell lines and tumor-derived material, where samples are resolved on SDS-PAGE, transferred to membrane, and developed with a horseradish peroxidase-conjugated secondary antibody for chemiluminescent visualization. The unconjugated format permits flexible pairing with anti-rabbit secondary reagents, and the phospho-specific epitope recognition supports studies of CDK inhibitor pharmacology, cell cycle synchronization, and chemotherapeutic response in human cancer models.