Microscopic evaluation of urine sediment by the cytology laboratory can provide valuable information to the clinician. While some crystal types are considered normal, others are abnormal and indicate disease. Traditional analysis within the cytology laboratory includes direct cytospin preparations and smears of the urine sample. Light microscopy with polarized light is then utilized to examine the slide preparations.

Many cytology laboratories have recently incorporated liquid-based technology for gynecologic and non-gynecologic specimen preparation. Specimens placed in the proprietary fluid are processed according to the manufacturer's directions with the ultimate result of a thin, circular layer of cells on the slide. The advantages of liquidbased methods include concentration of the cells into a thin layer, localization to a small area of the slide, minimization of background debris, and ability to make additional specimens from the same sample. When the liquid-based slide preparations of urine made in our lab were compared to the conventional cytospin smears,