Anti-Histone H2A.X (phospho-S139) Antibody

The phospho-S139 modification of histone H2A.X, commonly known as gamma-H2AX, is one of the earliest chromatin events triggered at DNA double-strand break sites and forms the basis of widely used DNA damage and repair assays.

This unconjugated rabbit polyclonal primary antibody from Antibodies.com was raised against the phosphorylated serine 139 epitope of histone H2A.X and detects the modified histone in human, mouse, and rat samples.

Supplied as a 100 µl vial at 1 mg/ml in phosphate buffered saline (PBS) with 0.05% sodium azide at approximately pH 7.2, the reagent is validated for Western blot and immunohistochemistry. In Western blot applications, the antibody is applied to acid-extracted histones or whole-cell lysates from cells subjected to genotoxic stress (ionising radiation, etoposide, hydrogen peroxide), producing a characteristic band near 15 kDa. In immunohistochemistry on formalin-fixed paraffin-embedded tissue, citrate-based antigen retrieval followed by overnight primary incubation yields discrete nuclear foci that overlap with established DNA damage markers.

Aliquot upon first use to limit repeated freeze-thaw cycles; the included 0.05% sodium azide acts as a microbial preservative. The polyclonal response provides broad recognition of the conserved phospho-S139 region across species, supporting consistent detection in human, mouse, and rat model systems.