Figure 4.

Maltodextrin-based formulations with iVAX extract enable production of conjugate vaccine molecules at low cost after high-temperature storage. Yields of carrier protein (PD) were measured from lyophilized 15 μL of reactions stored for up to 4 weeks at (A) room temperature (∼22 °C), (B) 37 °C, and (C) 50 °C. Unpaired two-tailed t-tests were used to compare the 0-week and 4-week timepoint for each condition in (A)–(C). P values showing the significance of the change in sfGFP yield for each condition between 0 and 4 weeks of storage are inset on the top right of each graph with the corresponding shape for each condition. An ordinary one-way ANOVA (95% confidence interval) with Dunnett’s multiple comparisons test was performed to determine the significance of the yields after 4 weeks of storage for each condition compared to the PEP formulation. Significance (adjusted p value <0.0001 is denoted by ****, 0.0001 to 0.001 by ***, 0.001 to 0.01 by **, 0.01 to 0.05 by *, and ≥0.05 by ns) is reported to the right of the 4-week timepoint marker for each condition in (A)–(C). CFE reactions were rehydrated with 15 μL of water and incubated at 30 °C for 4 h, then glycosylation was initiated, and samples were incubated for an additional 16 h at 30 °C. Yields of glycosylated carrier protein (PD) with a C-terminal glycosylation tag followed by a 6x-His tag were measured (D) and observed via anti-His Western blot (E) for reactions that were stored at 50 °C. (F) Estimated cost per dose of conjugate vaccines produced by CFE reactions stored for 4 weeks at each tested temperature. Error bars represent the standard deviation of four CFE reactions (n = 4).