Figure 4. Immunoblot showing disease-associated prion protein from chronic wasting disease–affected elk brain or mule deer brain, tonsil, spleen, and retropharyngeal lymph node before and after treatment with PNGaseF. Alternating lanes show before and after treatment for each tissue. PNGaseF digestion was done as described in Materials and Methods. Ten-milligram equivalents of tissue were used for PNGase F–negative lanes, and 4-mg equivalents of tissue were used for PNGase F–positive lanes. The blot was developed as described in Figure 3.