Figure 2 : A recombinant protein (Tth) purified from E. coli or ClearColi (CC) shows no signs of LPS contamination in Factor C based assays.

From: Biological Activity of Masked Endotoxin

Figure 2

Two different concentrations of Tth purified from E. coli BL21 Star™ (DE3) or ClearColi® (CC) BL21 (DE3) were analysed for LPS contamination using the LAL-assay (a) or the EndoZyme-assay (b). E. coli LPS 055:B5 (0.1 ng/ml or ~1 EU/ml) was used as a positive control. Detection range of the LAL-assay: 0.1 to 1 EU/ml, indicated by dotted lines. Detection range of the EndoZyme assay: 0.005 to 50 EU/ml. Mean and SD of three independent experiments are shown.