Figure 1. Comparison of Kick-in and Knock-in methodologies.

On the left is a schematic of a traditional knock-in along with the estimated duration of each step. Juxtaposed on the right are the corresponding steps for a kick-in; savings in time and cost versus the knock-in are highlighted by a little stopwatch. Low recombination rates (∼1∶10⁵) are associated with homologous recombination. To make several constructs, homologous recombination must be performed for each construct. In the kick-in system, homologous recombination is needed only once, even if several constructs are made.