Proflavine-Stained Cells (normal oral)

All human cells used in this study were collected following written informed consent from healthy volunteers as part of a protocol (IRB#13-06-759) approved by the University of Arkansas Institutional Review Board. Exfoliated oral epithelial cells were collected through an oral rinse consisting of a 30 sec rinse to remove food particles and bacteria that were discarded followed by a 90 sec collected rinse. The cell suspension was filtered through a 100µm cell strainer (Falcon, Bedford, MA) to remove mucus and washed three times by centrifuging at 200g for 5 min, decanting the supernatant, and resuspending in phosphate buffered saline (1x PBS, Sigma-Aldrich, St. Louis, MO). Cells were stained with proflavine at a final concentration of 0.01%(w/v) in PBS.