Comparison of capillary electropherograms of unmodified VSV-G pseudotyped lentivirus (VSVG) (1), PEGylated VSV-G pseudotyped lentivirus (PEG-VSVG) (2), and a control solution of monomethoxypoly(ethylene) glycol (10 mg/ml) activated by succinimidyl succinate (PEG) (3). Virus samples were diluted 1:2 with separation buffer (50 mM sodium phosphate-buffered saline, 10 mM sodium chloride, pH 7.0) prior to analysis. The samples were run on a PACE 5000 system with a 5-s injection time and a separation voltage of 12.5 kV at 22°C. AU, absorbance units.