Processing of Cytological Specimens

Immunocytochemistry can be a valuable tool for the determination of cellular contents from individual cell suspensions. Samples that can be analyzed include blood smears, aspirates, and swabs from any cellular site. Each sample is treated differently, and yet all the methods are interchangeable. There is no one way in which to prepare these types of cell samples for immunocytochemical analysis. This chapter will deal with the most common forms of cell sample—the swab, aspirate, and smear. Blood can be analyzed as a smear, but it presents more of a problem owing to the concentration of red blood cells. These cells have an oxidative-type function, and when using a peroxidase-based detection system, it can greatly interfere with the test. Concentrated cellular suspensions that exist in a low-viscosity medium make good candidates for smear preparations. Dilute cell suspensions existing in a dilute medium are best suited for the preparation of cytospins through cytocentrifugation. Cell suspensions that exist in a high-viscosity medium are best suited to be tested as swab preparations (1 ). The constant among these preparations is that the whole cell is present on the slide surface. For any intracellular reaction to take place, immunoglobulin must first traverse the cell membrane, which is intact in these preparations.