Anti-Chk1 (R323) Antibody

This rabbit polyclonal reagent from Antibodies.com detects Checkpoint Kinase 1 (Chk1), a serine/threonine kinase that mediates the DNA damage response and controls the G2/M cell cycle checkpoint. It was raised against a synthetic peptide spanning the region around residue R323 of human Chk1, a sequence segment near the kinase catalytic domain that is conserved among mammals.

Chk1 is phosphorylated at Ser345 primarily by the upstream kinase ATR when replication forks stall or DNA lesions accumulate. Once activated, Chk1 propagates checkpoint signals that delay mitotic entry and stabilize replication forks. Dysregulated Chk1 signaling is implicated in genomic instability and is a target of investigation in oncology, where Chk1 inhibitors are being evaluated as chemo- and radiosensitizers. Researchers therefore use Chk1-specific antibodies to track activation status, expression levels, and subcellular distribution in tumor models and DNA repair studies.

Each vial supplies 100 µl of antibody at 1 mg/ml in phosphate buffered saline (PBS), pH approximately 7.2, containing 0.05% sodium azide as a preservative. The unconjugated preparation gives researchers flexibility to pair it with a wide selection of secondary detection reagents or to label it for custom applications. Reactivity has been confirmed against human, mouse, and rat samples, supporting use across species in comparative tissue studies.

The antibody is validated for immunohistochemistry (IHC). On formalin-fixed paraffin-embedded sections, antigen retrieval in 10 mM citrate buffer at pH 6.0 is commonly employed before primary antibody incubation. Refrigerated storage is recommended to preserve activity, and aliquoting upon first use helps limit freeze-thaw cycles.