Figure 2.

Production and purification of USCTX. (a) Commercially available cell-free synthesis systems differ in their ability to produce USCTX (anticipated band size = 4.3 kDa). No such band was produced by the S30 Extract System (left) or the TnT T7 Insect Cell Extract Protein Expression System (right), but a band of the expected size was produced by the NEB PURExpress In Vitro Protein Synthesis System (middle, in duplicate to highlight reproducibility). (b) Purification of USCTX, showing the elution fractions E1–E3 from the His-Spin column. The red box indicates the area in which USCTX bands should appear.