Molecular Discrimination of Sheep Bovine Spongiform Encephalopathy from Scrapie
Figure 2. A) Scattergraph of antibody ratio and denaturation ratio obtained from each sample in Table 2, showing discrimination of scrapie, CH1641, CH1641-like, and bovine spongiform encephalopathy (BSE) samples. The antibody ratio is the SAF84/P4 ratio of the chemiluminescence signal relative to the SAF84/P4 ratio of the control scrapie loaded in each blot (Technical Appendix). The denaturation ratio, obtained from the SAF84 blot, is the ratio between the chemiluminescence signal with 3.5 mol/L and that with 0 mol/L. The vertical dashed line refers to the cutoff value of the antibody ratio, according to the Istituto Superiore di Sanità discriminatory Western blot (antibody ratio 2). The horizontal dashed line (denaturation ratio 0.4) shows the separation of BSE samples from all other transmissible spongiform encephalopathy sources. B) Scattergraph of proportions of diglycosylated and monoglycosylated PrPres bands from samples in Table 2. Results were obtained from guanidine hydrochloride–untreated samples in blots treated with SAF84. Classical scrapie samples are represented by black symbols, CH1641 by red symbols, and BSE samples by blue symbols. Filled symbols denote natural isolates and open symbols represent the experimental isolates.