Figure 4From: Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone mealsDetection of PrPScin brains of asymptomatic mice. A 10% brain homogenate from five (#1-#5) of six asymptomatic mice inoculated with 10–6 dilution of infected homogenate (Table 1) was prepared, and amplified by serial PMCA. Quadruplicate samples were analyzed after each round (R1–R4) of amplification by western blotting after digestion with proteinase K. One (#1 and #3), two (#5) and four (#2) of the quadruplicate samples were found to be positive for PrPSc after three or four rounds of amplification. No PrPSc signal was detected in #4 mouse. The eight lanes labeled “N” are samples in which only the PrPC substrate was treated in the same manner. Horizontal lines indicate the positions of molecular-weight markers corresponding to 37, 25, 20, and 15 kDa. nt: not tested.Back to article page