Fig. 2

Initial characterization of purified chimeric VLPs by TEM (transmission electron microscopy) and non-reducing PAGE. a TEM of negatively stained VLP preparations (from lane 6 in Fig. 1b). T = 4-VLPs are marked with arrows (for higher magnification see inset in the upper right corner); T = 3-VLPs are labeled with arrow heads (for higher magnification see insets in the lower left corner). Scale bars: 200 nm. Histogram insets show diameter distributions for T = 4- (light grey) and T = 3-VLPs (dark grey). Abscissa: diameter in [nm]; ordinate: VLP counts. Only entirely intact particles were counted, total number was 479. The VLP mean diameters were fitted by Gaussian curves and the maxima are indicated in Table 1. b Colloidal Coomassie stained 12% NuPAGE analysis of VLPs (from lane 6 in Fig. 1b) treated with increasing DTT-concentrations. Samples were incubated with or without DTT 15 min prior non-reducing buffer supplemented and heated to 60 °C, max: sample in reducing buffer after boiling. Mono- and multimeric forms of chimeric VLPs are indicated