LACK OF SPECIFICITY OF COMMERCIAL ANTIBODIES LEADS TO MISIDENTIFICATION OF ANGIOTENSIN TYPE 1 RECEPTOR (AT₁R) PROTEIN

Dear Editor

We read with great interest the letter from Eguchi et al. providing additional evidence to support the lack of suitability of commercial antibodies for detecting angiotensin type 1 (AT₁) receptor protein in experimental systems. The data from Eguchi and associates extend our previous report¹ by documenting the failure of two additional antibodies to specifically detect rat AT₁ receptor protein in Western blots of protein isolated from cells transfected with rat AT₁ receptors fused with a hemagglutinin tag. Including Eguchi’s letter and our paper, there are now independent publications from four different laboratories demonstrating lack of specificity of 7 commonly-used anti-AT₁ receptor antibodies available from reputable commercial sources^1–3 (Table 1). Indeed, it is notable that none of the antibodies tested have demonstrated specificity for AT₁ receptor protein. Thus, it is incumbent upon investigators to verify the specificity and suitability of anti-AT₁ receptor antibodies for their particular experimental application. Reviewers and journals should likewise require such verification.

Table 1.

Commercial antibodies shown to be unreliable for detecting AT₁R protein.

Antibody source	Species of AT1R used for testing	Reference
Abcam ab9391	rat	Eguchi et al.
	rat	Benicky et al.
Abcam ab15552	mouse and rat	Benicky et al.
Abcam ab18801	mouse	Herrera et al.
	mouse	Rateri et al.
	rat	Benicky et al.
Alomone AAR-011	mouse	Herrera et al.
	mouse	Benicky et al.
Santa Cruz sc-579	rat	Eguchi et al.
	mouse	Rateri et al.
	mouse and rat	Benicky et al.
Santa Cruz sc-1173	rat	Eguchi et al.
	mouse	Herrera et al.
	mouse	Rateri et al.
	mouse and rat	Benicky et al.
Santa Cruz sc-31181	mouse	Rateri et al.

Sincerely yours,