Ten commercial antibodies for alpha-1-adrenergic receptor subtypes are nonspecific

Abstract

Commercial antibodies are used widely to quantify and localize the alpha1-adrenergic receptor (AR) subtypes, alpha1A, alpha1B, and alpha1D. We tested ten antibodies, from abcam and Santa Cruz, using western blot with heart and brain tissue from wild-type (WT) mice and mice with systemic knockout (KO) of one or all three subtypes. We found that none of the antibodies detected a band in WT that was absent in the appropriate KO or in the KO that was null for all alpha1-ARs (ABDKO). We conclude that the antibodies we tested are not specific for alpha1-ARs. These results raise caution with prior studies using these reagents. For now, competition radioligand binding is the only reliable approach to quantify the alpha1-AR subtype proteins. Receptor protein localization remains a challenge.

Fig. 1

Western blots with α1-AR antibodies. Each panel shows the blot for one antibody tested with heart or brain tissue from a WT mouse and a mouse with genetic deletion of α1-AR subtypes: one (AKO), two (ABKO), or all three (ABDKO). Size markers are shown at far left and the 54 kDa marker is indicated on each blot. Note that no band with any antibody is present in WT but absent in KO indicating that no band is specific for an α1-AR