. 2011 Jun 7;6(6):e20928. doi: 10.1371/journal.pone.0020928

Table 1. Purification step, yield, and flagellin bioactivity^a of candidate vaccines.

	STF2.HA1	STF2R3.HA1	STF2R3.2xHA1
Expression	75% soluble	Inclusion bodies	Inclusion bodies
Refolding method	Rapid dilution	Rapid dilution	Rapid dilution
Chromatography	AEX, SEC	AEX, SEC	AEX, SEC
Yield (g purified protein/g cell past)	1.43	1.79	1.67
IL-8 induction (pg/ml)	383±39	1002±164	553±35

flagellin bioactivity was assessed by measuring secreted IL-8 with a sandwich ELISA (BD Biosciences) as previously described [9]. HEK293 cells in 96-well plates (n = 9) were stimulated with 278 ng/ml of each vaccine candidate for 16–18 hours at 37°C. IL-8 concentrations in medium were calculated from an IL-8 standard curve, and expressed as means ± SDs. IL-8 levels of cell control samples were < = 30 pg/ml.

Table 1. Purification step, yield, and flagellin bioactivitya of candidate vaccines.

Table 1. Purification step, yield, and flagellin bioactivity^a of candidate vaccines.