Relative levels of PrPScin brain homogenate from donor animals. Serial two-fold dilutions of brain homogenate from goat 3538 (A), 3558 (B), 30–75 (C) and reference sheep 3178 (D) were analyzed by western blot analysis and ELISA. Absorbance (A450) results from ELISA (−·-) are shown on the left y axis and density of the diglycosylated band determined from scans of western blot (vertical bars and inset image) on the right y axis. Starting wet weight equivalents per ELISA well or Western blot lane are shown on the x axis. Cut off limit for the ELISA (−−----------) was determined from the manufacturer’s negative control sample.