Canis ISSN: 2398-2942

Cerebrospinal fluid: cell count and differential

Synonym(s): CSF

Contributor(s): Vetstream Ltd

Overview

  • Cell numbers generally increase in acute inflammation and some other conditions.
  • Differential counts essential to diagnose etiology of central nervous system (CNS) pathology.

Sampling

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Tests

Methodologies

  • Total cell count - hemocytometer: Hematology: leukocyte (WBC) :
    • If using undiluted CSF count, use a capillary pipette to fill one side of hemocytometer. The number of cells x 1.1 = cell count/ul.
    • If using CSF diluted with Rosenthal's diluting fluid, fill a WBC diluting pipette up to the 'l' mark with diluting fluid and to the 'll' mark with CSF. Then fill each side of hemocytometer, wait 2 minutes for cells to settle, count all cells on both sides of the counting chamber: cell count x 0.6 = number of cells/ul.
  • For differential cell concentration use other techniques, eg sedimentation, centrifugation, membrane filtration or cytocentrifugation.
  • Sedimentation chamber prepared using small glass cylinders (cut off plain vacutainer tube):
    • Drop the smooth end of cylinder into melted paraffin wax, then place on a warm slide.
    • As the wax seals, a clean bead of wax encircles cylinder.
    • Place up to 1 ml CSF in chamber.
    • After 30 min carefully aspirate the supernatant.
    • Remove the cylinder by breaking the wax seal.
    • Fix and stain the sample.
  • Giemsa-stained smear for differential.

Availability

  • Widely available at commercial laboratories.

Technique (intrinsic) limitations

  • Cell counts may be falsely elevated by blood contamination.

Result Data

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Further Reading

Publications

Refereed papers


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