Estrogen Receptor (Clone SP1)
Rabbit Anti-Human Estrogen Receptor (ER) (Clone SP1, Catalog #M3010, M3011, M3014) Monoclonal Antibody is a rabbit monoclonal antibody intended for the qualitative detection of estrogen receptor (ER) α form in sections of formalin-fixed, paraffin embedded tissues. The antibody labels estrogen receptor-positive cells. Steroid hormone receptors exhibit a high affinity and specificity for their ligands. The human estrogen receptor (ER) exists in two forms, ERα and ERβ. The receptors have a high degree of homology in their DNA binding and ligand binding domains and can form heterodimers. However, the two ERs signal in different ways; for example, ERβ does not potentiate the nuclear transcription factor AP-1 when complexed with oestradiol, whereas ERα does. This suggests that ERα and ERβ may have different roles in gene regulation and their relative levels within tissues may influence cellular responses to oestrogens.
Unique Strengths/Highlights:
- More sensitive than Mouse Monoclonal 1D5
- 1D5 fails to identify 6% of ER positive patients compared to SP1
- SP1 represents an improved standard for ER
SP1 Publications:
Cheang MC, Treaba DO, Speers CH, Olivotto IA, Bajdik CD, Chia SK, Goldstein LC, Gelmon KA, Huntsman D, Gilks CB, Nielsen TO, Gown AM. Immunohistochemical detection using the new rabbit monoclonal antibody SP1 of estrogen receptor in breast cancer is superior to mouse monoclonal antibody 1D5 in predicting survival. J Clin Oncol. 2006 Dec 20;24(36):5626-8. (View Abstract)