Anti-Rpb1 (phospho-S1619) Antibody

Phospho-specific polyclonal antibody raised in rabbit against Rpb1, the catalytic subunit of RNA polymerase II. The reagent selectively recognizes Rpb1 phosphorylated at serine 1619, a modification positioned within the C-terminal domain heptad repeats and linked to transcription cycle regulation, promoter-proximal pausing, and co-transcriptional processing events. Supplied as 100 µl of unconjugated antibody at 1 mg/ml in phosphate buffered saline (PBS) containing 0.05% sodium azide at approximately pH 7.2, the preparation is calibrated for Western blot and immunohistochemistry workflows. Reactivity has been confirmed on Human, Mouse, and Rat samples, making the antibody useful for comparative studies of transcriptional control, chromatin-associated signaling, and stress responses across these model systems. The polyclonal format provides multi-epitope recognition around the phospho-S1619 site, which can improve detection of the modified polymerase under varied fixation and lysis conditions. For short-term use, keep the vial refrigerated in the dark; for extended storage, aliquot and freeze at -20°C or below to minimize freeze-thaw cycles of the working stock. Sodium azide is included as a preservative, so the reagent should not be added directly to live-cell or live-tissue preparations. Aliquoting upon first use is recommended to preserve antibody activity over multiple experiments. This reagent is intended for research use only and is offered by Antibodies.com as part of its primary antibody range targeting post-translational modifications of the transcription machinery.