HIV-1 isolates display different characteristic plaque size. (a) Mean plaque area of uninhibited HIV-1 isolates with subtype and coreceptor use, indicated in parentheses. Each dot represents the mean plaque area per/well given in microns (Y axis). Horizontal bars indicate the mean of four to nine experiments run in triplicate wells. Statistically significant differences according to Kruskal-Wallis test and Dunn’s Post test. * < 0.05; *** < 0.001. (b) MN(P) exhibit larger plaques (left) while 92UG024 exhibit smaller plaques (right) regardless of virus titer.