Modified Papanicolaou staining for oral swab samples stored long term.

Pathologists collect swab samples for Papanicolaou (Pap) staining to diagnose various diseases including cancer and HIV. Time constraints and limited resources, may preclude staining a sample immediately. To re-confirm results, samples must be frozen for later analysis. We present a method for Pap staining cells that have been stored long term. An effective method for Pap staining of frozen cells should enable flexibility for processing samples.