The infected ReN cells were washed with PBS and then incubated with Accutase (Millipore) for 5 minutes. The cell pellets were resuspended in PBS supplemented with 2% serum replacement solution (Life Technologies) and 2% B27, and then passed through a cell strainer filter (70 μm Nylon, BD Biosciences). The cell concentrations were adjusted to 2 × 106 cells/ml and then enriched by using FACSAria cell sorter (Broad Institute of MIT and Harvard, Cambridge, MA, USA). GFP and/or mCherry channels were used to detect the expression of the transfected genes in the individual cells. The sorted/enriched cells were maintained in normal proliferation media.
