WHV DNA expression in serum, liver, and lymphoid cells of 260/M woodchuck after inoculation with serum from liver WHV DNA–negative 3B/M offspring. Five micrograms of total DNA from liver biopsies collected at ∼2 months before (1) and 2 months after (2) inoculation and at autopsy (3), and 1 μg of DNA from autopsy PBMCs, isolated splenocytes, and bone marrow obtained at 3.5 months after inoculation or from 50 μL of autopsy serum, were tested for WHV DNA by nested PCR using WHV C gene–specific primers and hybridization to WHV DNA probe. DNA from serum of a WHsAg-positive chronic carrier was included as a positive control, and water instead of DNA and a mock sample extracted in parallel with test samples were used negative controls. Positive samples showed the expected 428-bp nucleotide fragment noted by arrowhead.