Anti-PIK3CA Antibody

Supplied as 50 µl of unconjugated rabbit polyclonal antiserum, this IgG reagent from Antibodies.com recognizes the catalytic subunit of class IA phosphoinositide 3-kinase. Validated for western blot, immunohistochemistry on paraffin-embedded sections, immunoprecipitation of PI3K signaling complexes, and flow cytometry, the antibody detects endogenous p110α in human, mouse, and rat samples, producing the characteristic ~110 kDa band expected for the full-length subunit.

PIK3CA is among the most frequently mutated oncogenes in solid tumors. Two hotspot gain-of-function substitutions dominate the landscape — H1047R in the kinase domain and E545K in the helical domain — together accounting for the majority of reported PIK3CA alterations and driving constitutive activation of the PI3K/AKT/mTOR axis. These variants are recurrent in HR+ HER2− breast cancer, colorectal cancer, and endometrial cancer, and are also found at lower frequency in head and neck, gastric, bladder, and PIK3CA-related overgrowth spectrum disorders. Researchers use this reagent to confirm expression of wild-type and mutant p110α, benchmark the cellular response to isoform-selective inhibitors such as alpelisib and next-generation mutant-selective compounds (inavolisib, RLY-2608, LOXO-783, STX-478), and profile downstream phosphorylation of AKT, PRAS40, S6K, and 4E-BP1 in cell line, xenograft, and inducible knock-in models.

The polyclonal format provides multi-epitope coverage across the ~1068-residue p110α protein — spanning the ABD, RBD, C2, helical, and kinase domains — which improves recovery of truncated splice variants and helps overcome epitope masking that can occur in heavily fixed tissues. Aliquot upon receipt and store at -20 °C in a working aliquot to limit freeze-thaw cycles, where short-term refrigerated storage is acceptable for active use over several weeks.