Anti-ESR1 (phospho S167) Antibody

Rabbit polyclonal IgG antibody from Antibodies.com that selectively recognizes estrogen receptor alpha (ESR1) when phosphorylated at serine 167. The phospho-S167 epitope marks an activated, transcriptionally engaged form of the receptor generated downstream of MAPK-driven signalling, making this reagent a useful probe for tracking ligand-independent and growth factor-driven ERα activity in breast cancer cell models and tumour lysates.

Supplied as 50 µl of unconjugated antiserum in a single-use vial, the antibody is validated for Western blot on human samples and is compatible with standard chemiluminescent and infrared secondary detection workflows. The polyclonal format provides broader epitope coverage around the phospho-S167 site, which helps when assessing dynamic changes in receptor modification in response to oestrogen, growth factors, or kinase inhibitors.

Typical uses include confirming pathway activation in MCF-7 and T47D breast cancer lines, monitoring resistance mechanisms to endocrine therapies such as tamoxifen, and characterising ERα status in patient-derived tumour samples where S167 phosphorylation has been reported to correlate with poorer outcomes and altered treatment response.