Anti-Chk1 (S291) Antibody

Produced by Antibodies.com as a rabbit polyclonal reagent, this antibody recognizes Checkpoint Kinase 1 (Chk1) when phosphorylated at the serine 291 residue, a modification linked to regulatory events within the DNA damage response pathway. The unconjugated antibody is supplied as 100 µl of a 1 mg/ml stock in phosphate buffered saline (PBS) containing 0.05% sodium azide at approximately pH 7.2, and it is validated for Western blot and immunohistochemistry workflows with confirmed reactivity against human, mouse, and rat samples.

Chk1 operates as a serine/threonine kinase that coordinates cell cycle arrest and DNA repair after genotoxic stress. Phosphorylation at S291 represents a regulatory site distinct from the well-characterized S317 and S345 ATR-target residues, so detection of this epitope supports studies of Chk1 function outside canonical ATM/ATR signaling. Investigators commonly apply this reagent to lysates from cultured cells and to fixed tissue sections to map kinase activation states, probe checkpoint fidelity in tumor models, and characterize responses to small-molecule Chk1 inhibitors in vitro.

The polyclonal backbone offers recognition of multiple epitopes surrounding the S291 phospho-mark, which improves tolerance for minor variations in sample preparation. Each vial contains 100 µl ready for routine bench handling, and the included sodium azide preservative maintains microbial stability through repeated use. Aliquots are recommended to limit freeze-thaw cycles on the working stock.