Processing of Cytological Specimens

Abstract

Individual cells often need to be examined with antibodies apart from the surrounding tissue. They may be cells in fluid, cells encased in mucus from a swab, or cells directly extracted from a piece of tissue. Cells can be viewed on a glass slide as cell smears produced from a cell enriched source, introduced as a touch preparation from a piece of wet tissue, concentrated on a slide by the use of a cytocentrifuge, or applied directly to a slide from a solid medium such as a cotton swab. These cell preparations can then be optimally fixed in weakly or nondenaturing solutions such as acetone or those that are alcohol based. They can also be postfixed in formalin if desired. Incubation in buffers containing 0.25% Triton X-100 and 5% dimethylsulfoxide (DMSO) allow for easier antibody penetration. The endogenous peroxidase enzyme or oxidative compounds can be quenched in a mild hydrogen peroxide solution. The sections are then ready to test with antibody after an incubation in a normal serum solution blocks any available charged sites.