TKT and viral infectious disease: At 1, 3, 7, 10, 14, and 21 days postinfection, we collected the spleens, livers, and salivary glands from euthanized animals and assessed viral infection and production by determining virus titers in these tissues.19, 38 The viral titers in each of the organs from mice injected with control EGS (i.e., mCSP-V832-C, mCSP-SER-C, or M1-TK) constructs were identical to those in the same organs from mice injected with only PBS, suggesting that these control EGSs do not affect MCMV infection and production in vivo (Figures 6A–6C).