Cell yield obtained with various cytopreparatory techniques for urinary cytology.

Information concerning the main pitfalls of cytopreparatory techniques, e.g., cell loss, is of paramount importance for general acceptance of the routine use of urinary cytology. Therefore, we studied the cell yield obtained with five Papanicolaou and two May-Grünwald-Giemsa (MGG) smear techniques commonly used in diagnostic cytology laboratories, and compared the results with those obtained with the Millipore filter technique. All smear methods using wet fixation gave very low cell harvests (2-26%), and all methods using air drying gave high cell yield (55-95%), the spray fixation method giving intermediate results (about 40%). Since the morphometric studies showed that there was no preferential cell loss, the cells remaining on the slides can be considered representative of the original cell population. However, if the cell concentration of the urinary sample is extremely low, the Millipore filter and the albumin MGG methods, in both of which cell loss is minimal, are recommended. The results obtained with the spray fixation Papanicolaou method are quantitatively acceptable and qualitatively excellent.