The differential cytology of cerebrospinal fluids prepared by cytocentrifugation

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The total cell count and differential count are an essential part of the analysis of a specimen of cerebrospinal fluid (CSF). The accuracy of the differential count has been improved significantly by the use of such concentrating techniques as sedimentation, filtration, and centrifugation.1–10 The cytocentrifuge (Cytospin, Shandor-Elliot), which we have used since 1974, concentrates the formed elements of the fluid directly onto a slide without significant alteration of morphology.

This paper reports our estimate of the normal differential count and the findings in spinal fluids examined over a 9-month period.

Material and methods

From January to September 1974 approximately 1,600 cerebrospinal fluids were examined. The appearance of the fluid was noted, and in all instances a cell count and quantitative protein measurement were made. Other tests (e.g., glucose, protein electrophoresis, tests for syphilis) were performed if ordered by the clinician. The cells were counted in a hemocytometer and if there was 1 cell/μl or less, a differential count could be waived at the discretion of the technologist. Slides were prepared from the remaining fluids by centrifuging a mixture of 0.5 ml fluid and 2 drops 22% bovine albumin at 1,500 rpm for 2 minutes in a cytocentrifuge. The air-dried smears were stained with Wright’s stain.

All smears were reviewed and those in which at least 25 leukocytes were present and well preserved were used in this study. This group comprised 571 fluids from 423 patients. Differential counts were tabulated without knowledge of the patients’ clinical statuses.


To establish . . .



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