Figure 5. Dose–response relationship for A) incubation period and B) probability of infection of bovine PrP–expressing mice. Data were derived from an endpoint titration of 10% (wt/vol) frontal cortex homogenate from a patient with variant Creutzfeldt-Jakob disease. This homogenate was inoculated into tgBov mice (20 μL by intracerebral [ic] route; Table 1). This procedure was used to establish a model that estimates infectious titer in a homogenate on the basis of incubation period and the probability of infection in inoculated mice. Model plots are indicated by solid lines. +, observed value. LD50, 50% lethal dose.