[KO Validated] Anti-CDKN1A/p21 Rabbit PolymAb® Monoclonal Antibody for WB, IF/ICC, ELISA - P38936 / P39689

Core Product Specifications and Parameters

Biological Background: CDKN1A/p21 Function and Localization

• CDKN1A/p21, also known as CIP1, WAF1, SDI1, MDA-6, and CAP20, is a cyclin-dependent kinase inhibitor that plays a central role in cell cycle regulation, senescence, and DNA damage responses.
• It binds to and inhibits cyclin-dependent kinase (CDK) complexes, preventing the phosphorylation of critical substrates such as RB1, thereby blocking cell cycle progression at the G1/S and G2/M checkpoints.
• Plays an important role in controlling cell cycle progression and DNA damage-induced G2 arrest, acting downstream of p53/TP53 and also in p53-independent pathways mediated by CREB3L1 (by similarity).
  Related references:
  PMID:9106657
• At replication forks, p21 competes with POLD3 for PCNA binding, directly inhibiting DNA synthesis by DNA polymerase delta and contributing to replication stress responses.
  Related references:
  PMID:11595739
• Exhibits dual functions: at low stoichiometry it promotes the nuclear assembly and kinase activity of cyclin D-CDK4 complexes, while at higher ratios it inhibits the same complex (by similarity).
• Subcellular localization spans both the nucleus, where it exerts canonical CDK-inhibitory and transcriptional regulatory functions, and the cytoplasm, where it may influence apoptosis and motility.
• Expressed ubiquitously in adult tissues, with notably lower levels in the brain, consistent with its broad role in proliferation control.
• Post-translational modifications including phosphorylation and acetylation modulate stability, localization, and interactions; it also contains a zinc-finger domain, underscoring its multifunctional nature.

Experimental Guidance and Technical Tips

• As a recombinant rabbit monoclonal antibody (PolymAb®), it offers high lot-to-lot consistency and specificity, suitable for WB, IF/ICC, and ELISA.
• For Western blot, validate using lysates from cells with elevated p21 (e.g., DNA damage-treated or serum-starved cultures); knockout cells are ideal negative controls to confirm specificity.
• In immunocytochemistry/immunofluorescence, optimize fixation and permeabilization; expect nuclear and cytoplasmic staining, and consider co-staining with proliferation markers.
• For ELISA, pairing with a capture antibody or direct detection may be tested, ensuring compatibility with the recombinant immunogen.
• Reactivity with both human and mouse makes this antibody versatile for translational studies; always titrate in your own experimental system.

CamelBio: Your One-Stop Sourcing Bridge

• CamelBio serves as a comprehensive IVD raw-material partner, connecting diagnostic developers and research laboratories with high-quality antibodies like this KO-validated anti-CDKN1A/p21 PolymAb® for cell cycle and cancer-focused assays. We offer validated antibody pairs, optimized monoclonal and polyclonal antibodies, bulk ancillary reagents, and support for custom rare-target sourcing, all backed by supply chain reliability to streamline your workflow from concept to clinic.