An example agarose gel showing the efficiency of concatenation for library variants 1–5 using enzymes from different commercial sources. Performance was quantified for each reaction by the percentage of fully assembled 5 × amplicon (marked by blue triangles). The NEB Golden Gate assembly kit was shown to concatenate the library variants more efficiently, increasing the amount of fully assembled product to 40%. A more detailed comparison can be seen in the Supplementary Fig. S2.