Fig. 1. Standard curve of the ELISA assay used to measure plasma testosterone (T)
concentrations (filled circles). The curve represents the percentage T bound
to the antibody (B/B0x102) as a function of the T
concentration added to the assay well. The graph also shows the curve obtained
by assaying T in a house finch plasma sample at various dilutions (open
circles). Each point represents one assay well.