Abstract
Measuring corticosterone (Cort) in bird feathers has become increasingly popular as a non-invasive method of obtaining an integrated profile of Cort exposure during the period of feather replacement. Most studies use antibody-based assays to assess Cort levels in feathers [radioimmunoassays (RIA) or enzyme immunoassays (EIA)]. However, it is still unclear whether differences in Cort can be reliably and consistently detected in feathers using antibody-based assays, in part because it is not known how much Cort is present in feathers and antibodies can differ in their ability to detect their antigens. In this study, we tested six commercially available polyclonal Cort antibodies in a feather Cort RIA in nine species. We found that different antisera detected very different levels of Cort in feathers. Additionally, we found that the broad patterns of Cort across species were not the same when measured with different antibodies. Further analysis by mass spectrometry indicated the presence of very little Cort in the feathers of any of the five species tested, suggesting that antibodies were instead binding with Cort metabolites or other substances. These data indicate a potential hidden source of variability when measuring feather Cort with antibody-based tests. The data further suggest caution in cross-species comparisons because patterns seen in feather Cort may reflect artifacts of the specific antibody used in the assay.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call