cytocentrifugation

Cytocentrifugation is a laboratory technique used to prepare cells from suspensions for microscopic examination by depositing them onto a slide in a thin, uniform monolayer. It is widely used in clinical cytology to analyze cells from small-volume samples and scarce fluids.

Principle and procedure

A cell suspension is loaded into a disposable deposition chamber that sits on a microscope slide, often with a filter or membrane to assist deposition. When centrifuged at moderate g-forces (typically several hundred to about a thousand g) for a short time, cells are driven onto the slide and form a concentrated, evenly distributed monolayer. The slide is then fixed and stained for light microscopy. Pre-coated slides or coatings such as poly-L-lysine improve cell adhesion. Different commercial cytocentrifuge systems may employ slightly different chamber designs, but the core concept is rapid concentration and even distribution of cells onto a small slide area.

Applications

Cytocentrifugation is particularly valuable for body fluids (cerebrospinal, pleural, peritoneal, ascitic fluids; urine sediments) and bronchial or nasal washings, where cell numbers are limited. It also enhances cytology of fine-needle aspirates and small biopsies by producing high-quality slides suitable for routine staining and ancillary studies, including immunocytochemistry and molecular assays.

Advantages and limitations

The technique concentrates sparse cells, preserves morphology in a monolayer, and reduces overlapping cells, facilitating assessment and ancillary testing. It is relatively rapid and compatible with various stains. Limitations include potential cellular distortion from mechanical forces, possible artifacts from fixation or air drying, and the need for appropriate optimization for different sample types. Cytocentrifugation is often used in conjunction with conventional smear methods rather than as a universal replacement.