A panel of multi-color fluorescent DENV2 with comparable replicative abilities.

A) Multi-step replication kinetics of multi-color fluorescent DENV2. Confluent Vero cells were infected with one virus at MOI = 0.01. The culture media was sampled from the flask every 24 hours. Infectious virus titer in the media was assayed by foci-forming assay. B) Focus images of the wild-type (16681) and the multi-color DENV2 (top panel) and the bar graph comparing the sizes of their foci (bottom panel). Focus size was quantified by the number of pixels that it occupied on a digitized image taken on ELISpot reader. Each bar represents the average of the measured focus sizes and the error bars represent standard deviation. Between 143 and 713 foci were used for focus size quantification. C) Representative scatter plots of K562-CD209 infected with DENV2-eGFP and DENV2-mCherry. The first (with DENV2-eGFP) and the second (with DENV2-mCherry) infections were 24 hours apart. The infected cells were analyzed 3 days post infection. In the case of co-infection (right plot), the cells were infected by both viruses at the same time and analyzed 2 days post infection. D) Comparison of infection percentages of the second virus in K562-CD209 between the presence (diagonal-stripe bars) and the absence (empty-bar) of the first virus infections. The infection percentages in the absence of the first virus infections are normalized to 100% for comparing the extent of reduction (or exclusion) conferred by the first virus. E) Histograms of fluorescent intensities for each fluorescent reporter measured from populations of K562-CD209 infected with single virus, and co-infected with two, three, and four reporter DENV2 of different colors.