Anti-MEK1/2 (phospho-S222/226) Antibody

The MAPK/ERK signaling cascade is a central regulator of cell proliferation, survival, and differentiation. Phosphorylation of MEK1 (MAP2K1) and MEK2 (MAP2K2) at serine residues 222 and 226 within the activation loop is the activating modification imposed by upstream RAF kinases, and detection of this phospho-epitope is widely used to report pathway activation in research samples.

This polyclonal rabbit antibody from Antibodies.com selectively recognizes the dually phosphorylated S222/S226 form of MEK1/2, enabling researchers to monitor activation-state signaling in both cell lysates and tissue sections. Validated applications include Western blot and immunohistochemistry, with cross-reactivity confirmed against human, mouse, and rat samples, covering the most commonly used model systems in oncology and signal transduction studies.

The reagent is supplied as 100 µl of affinity-purified antibody at 1 mg/ml in phosphate buffered saline (PBS) with 0.05% sodium azide, approximately pH 7.2, and is unconjugated for compatibility with standard HRP, fluorescent, or chromogenic detection workflows. The polyclonal format broadens epitope coverage and improves tolerance for minor sequence variation between the MEK1 and MEK2 paralogs.

Suggested research contexts include profiling RAF/MEK/ERK pathway activity in tumor biopsies, evaluating cellular responses to small-molecule MEK or RAF inhibitors in cell-line panels, and time-course studies of growth-factor-stimulated signaling in primary cultures.