Fig. 4c

Cells were dissociated into single cells with 30% TrypLE as described elsewhere in this study and then incubated with fluorophore-conjugated antibodies, designed against cell surface markers, diluted in 1% KSR, for 30 minutes at 4 ℃. Following incubation, cell suspensions were washed with PBS and finally resuspended with 1% KSR, supplemented with DAPI counterstain. Unless otherwise stated, all analyses were done on live, single cells and contaminating MEFs were removed prior to data acquisition. Flow cytometry measurements were recorded on the LSR Fortessa instrument and analysed on FlowJo v10. FACS isolation of cells were carried out on the BD FacsARIA Fusion instrument.