Fluorescence activated cell sorting/scanning (FACS)

The washed cells were dissociated using 0.25% trypsin/0.02% (Ethyelendiaminetetraacetic acid) EDTA solution to obtain a cell suspension which was centrifuged at 400 × g/4 °C for 5 min. The cells were re-suspended in 500 μl PBS containing 1% (w/v) bovine serum albumin (BSA) and centrifuged at 400 × g/4 °C for 5 min. This washing step was repeated 3 times. The final cell suspension in PBS with BSA was subjected to FACS analysis using BD FACS Calibur instrument. FACS data was analyzed using Flow Jo 9.8.5 software.