Mean larval weight (MLW) gain of cohorts of M. sexta neonates (n = 10) fed mixtures of sonicated cell extracts (L) and culture supernatants (S), at dilutions of 1∶5, 1∶10 or 1∶20. Samples were mixed at a ratio of 50 µl of lysate (L) to 950 µl of supernatants (S). Samples were taken from the cosmid mutant AKO (figure 1) and pBAD30 expression constructs containing either nothing, “V”, or the tcdA1 gene only, “pA” [22]. Error bars represent the standard error. The more potent the toxic effect, the smaller the mean larval weight. A key using the data column fill pattern is given above the graph to assist in the interpretation of the predicted TC subunit contents of the test samples. The indicators * and ** are discussed in text. Two sample t-test comparisons were used to confirm statistical significance in mean weight differences at 99% confidence between the following samples discussed in the text; [AKO(S)+V(L) 1∶5] vs. [AKO(S)+pA(L) 1∶5]: t = 47.75, P<0.001, df = 18 and [AKO(S)+pA(L) 1∶20] vs. [V(S)+pA(L) 1∶20]: t = 11.84, P<0.001, df = 18.