FIG. 11.
PCR detection of RCMV DNA in several organs of RCMV- and RCMVΔR33-infected rats. To detect viral DNA in organs from either RCMV- or RCMVΔR33-infected rats, PCR was performed on serial dilutions of DNA that was purified from these organs. At each indicated time point, the results are shown for three RCMV-infected rats (open bars) and three RCMVDR33-infected rats (black bars). The height of each bar indicates the maximum dilution of a given DNA isolate with which a positive PCR result could still be obtained. ∗, below detection level (the number of virus genome copies in these samples is smaller than 300). We were able to detect a minimum of approximately 300 genome copies in 1 μg of tissue DNA (data not shown). †, The five samples indicated by ∗ on day 28 p.i. were infected with RCMVΔR33. The samples taken on day 28 p.i. were obtained from the experiment in Fig. 9, in which the rats were infected with 1 × 106 PFU of virus. All the other samples were taken from rats that were infected with 5 × 106 PFU of virus.