What is the recommended method for preparing a cerebrospinal fluid (CSF) sample for a differential count?

The recommended method for preparing a cerebrospinal fluid (CSF) sample for a differential count is through cytocentrifugation. This technique involves spinning the CSF sample in a centrifuge at a low speed, which allows cells to concentrate at the bottom of the centrifuge tube while the supernatant fluid is removed. This results in a cell pellet that can be easily transferred onto a microscope slide, creating a thin layer of cells for analysis.

Cytocentrifugation is especially effective for CSF samples because it preserves cell morphology, enhances the number of cells available for examination, and helps separate cellular components from the fluid. The method ensures better visualization of the cellular components, which is crucial for accurately determining the types and numbers of cells present, allowing for a reliable differential count.

In contrast, other methods like the direct smear or layering technique may not provide the same clarity or concentration of cells, making it more challenging to perform a differential cell count accurately. The filtration method is also less suitable for CSF samples, as it may not effectively retain cells in a concentrated form for examination.