What is the preferred fixative for cytology slides?

The preferred fixative for cytology slides is 95% methanol. This is because methanol effectively preserves cellular structures and morphology while preventing autolysis and decay of the cells. It permeates the tissues rapidly, allowing for quick fixation, which is crucial in maintaining the integrity of cellular details for microscopic evaluation. Proper fixation is essential for obtaining accurate diagnostic information from the cytology slides, and methanol is widely used in clinical laboratories for this purpose.

While formalin is commonly used for tissue fixation, it can introduce artifacts and distort cellular morphology, making it less suitable for cytological preparations where maintaining cellular detail is critical. Ethanol, particularly at lower concentrations like 70%, may not provide the same level of fixation quality as 95% methanol, as it can lead to cell shrinkage and altered appearances. Acetone, while a powerful fixative, can also lead to excessive cell distortion and is not typically used for routine cytological preparations where fine details are necessary.