Performance of the homogeneous FRET assay for recPrP (upper table) and PrPC from murine N2aPK1 cell lysates (lower table). The assay was evaluated according to three parameters: coefficient of variation (%CV), signal-to-noise ratio (S/N) and the Z′ factor. Acceptable values were: %CV values < 10% S/N > 8 and Z′ > 0.5.