Variation of CIMM-HCV isolates. A) Plot of entropy differences between HCV isolated in our system and control sequences. Normalized Shannon entropy values for 5'UTR sequences isolated by our in vitro system were subtracted from values determined from control sequences obtained from the HCV sequence database. A negative number is a base that has more variation in the isolates, while a positive number has more variation in the control set of sequences. B) Variation in the bases of 081 HCV isolates. The 081 serum sequence is used for the figure, with changes in the isolates indicated. There were 9 positions where the consensus changed for one or more isolates. The figure is adapted from Lyons et al. .