Fig. 1. Standard curve of known amounts of 6xHis-NencHHwt ELISA. The x axis represents the amount of peptide added per well (100 µl). Absorbance was read in a multiwell reader at 405 nm. Values of OD are means ± S.D. (N=4); correlation coefficients of the fitted curves are >0.99 for all the data (R=0.9937, S.D.=0.44, P<0.001).