Cytologic cell collection, suspension and preservation for automated screening procedures

Since disaggregation for monodispersion is optimal when the specimens are suspended in solutions of low alcohol content, we evaluated a modified Davis' solution as a collection and suspension medium. The preservation of specimens maintained at room temperature (21 C) in this solution, which contained only 10% ethanol instead of the usual 20%, was evaluated both qualitatively and quantitatively. Control slides were made on day 1, and experimental slides were made on days 3, 7, 14, 21 and 28. The slides were evaluated by a cytotechnologist and confirmed by a pathologist for the onset of degenerative changes and loss of diagnostic value. The slides were also quantitatively analyzed by a semiautomatic instrument, the Cyto-Tally, adding substantial numerical value to the inquiry. The fragility of leukocytes was evident by the 14th day. Squamous cell degeneration was seen in the interval between two and four weeks depending on the initial state of the specimen. However, the specimens were of diagnostic value for up to four weeks.