Fig. 1.

Specific infectivity of DENV1 virions produced in people and laboratory cell lines. (A) Plasma from six subjects experiencing primary DENV1 infections was used to infect C6/36 and Vero cells. Viral-specific infectivity in human plasma and cell culture supernatants (Vero and C6/36 cells) was estimated by dividing the number of infectious virions by the number of viral genomes in each sample. (B) Specific infectivity of DENV1 viruses in human plasma and respective cell culture isolates. Cell culture virions are color-coded to match their respective plasma virus sample. Infectious virus titers and viral genome copies were the results of average values from two technical replicates in a single experiment. Specific infectivity for each virus was calculated from the above-calculated average values. Lines indicate the mean. Two-way ANOVA with a Tukey’s multiple comparisons test was performed to compare specific infectivity differences among plasma DENV1 samples and their cell culture isolates.