Anti-eIF2α (phospho-S51) Antibody

Phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2 at serine 51 is a central regulatory switch in the integrated stress response, where the kinases PERK, GCN2, HRI, and PKR converge to slow global protein synthesis while selectively translating stress-response transcripts. This affinity-purified rabbit polyclonal reagent from Antibodies.com specifically recognizes the phosphorylated S51 epitope on eIF2α, leaving the unphosphorylated protein largely undetected, so it serves as a discriminating probe for endoplasmic reticulum stress, amino acid deprivation, oxidative challenge, viral infection, and heme-regulated translational control studies. Supplied as 100 µl of unconjugated antibody at 1 mg/ml in phosphate buffered saline with 0.05% sodium azide at approximately pH 7.2, the reagent performs in western blot and immunohistochemistry workflows against human, mouse, and rat samples. Researchers commonly pair it with total eIF2α antibodies to derive phospho-to-total ratios as a quantitative readout of stress-pathway activity in cell lysates and fixed tissue sections. The 0.05% sodium azide acts as a preservative, allowing brief benchside handling while the vial is otherwise refrigerated for stability, and a 1 mg/ml starting concentration gives ample headroom for dilution series across membranes and slide-mounted specimens.