Duration of siPOOL silencing is similar to other siRNAs and depends on the cell line and the target gene. Gene silencing can typically last from 4-7 days. Cells with a high proliferation rate or highly active genes may experience shorter durations of RNAi-mediated silencing. A re-transfection of siPOOLs or transfection at higher initial siPOOL concentrations may be performed to extend duration of silencing.