D12345 GST-L1 forms capsomeres as demonstrated by two independent techniques and retains immunoreactivity with monoclonal antibody 16A. a, TEM of D12345 GST-L1 showing capsomere formation. TEMs of COPV GST-L1 and HPV16 GST-L1 capsomeres included for reference. Size bars represent 100 nm. b, Immunoblot of D12345 sucrose density gradient fractions with anti-AU1, with peaks for protein sedimentation markers indicated as arrows and corresponding densitometry analysis shown below. c, COPV GST-L1 as positive control. Immunoblot of COPV GST-L1 sucrose density gradient fractions with with anti-AU1. Standards are indicated as in b, and corresponding densitometry analysis is shown below. The amount of GST-L1 in the fractions was plotted as the percentage of total GST-L1 protein. Protein standards used were hemoglobin (4.5 S), catalase (11 S) and beta-galactosidase (19 S). d, Quantitative ELISA testing the immunoreactivity of D12345 GST-L1, HPV16 GST-L1 (positive control) and COPV GST-L1 (negative control) with the anti-HPV16 VLP monoclonal antibody 16A. A representative example of 2 independent experiments is shown.