Rehydration of air-dried smears. An alternative method for cytologic analysis of exfoliative cells

OBJECTIVE: To compare the cytologic characteristics of gastric mucosal cell smears prepared by air drying and rehydration prior to alcohol fixing with cells wet fixed in alcohol. STUDY DESIGN: Gastric mucosal cells were obtained from 55 consecutive patients undergoing gastroscopy. Paired smears were made, one immediately fixed in 95% ethanol for 20 minutes (wet fixed WF]) and the other air dried for at least 20 minutes prior to rehydration with normal saline for 30 seconds and fixation in 95% ethanol for 20 minutes (air dried/rehydrated/fixed ARF]). Both slides were stained by the Papanicolaou method. Coded slides were examined blind and graded 1 (superior), 2 (satisfactory) or 3 (poor) with respect to staining of chromatin, nuclear membrane, nucleoli, cytoplasm/cell border and group morphology. Histology confirmed a benign disease process or normal mucosa. RESULTS: Comparing grade 1 versus grades 2 and 3, ARF slides were significantly better than WF slides for all cytologic features (P < .05). Comparing grade 1 and 2 versus grade 3, there was no significant difference between ARF and WF slides (P > .05) (chi 2 analysis). CONCLUSION: The cytologic features of ARF smears of gastric cells were equal or superior to those of WF smears. This method of preparing smears is simpler and avoids some of the problems of ethanol fixation of wet smears.