In general, use the following equation to calculate CSF cell count:
Cells/µL = # of cells counted x dilution / # of large squares counted x 0.1µL (chamber depth)
For an undiluted specimen in which 10 squares are counted:
(total cells counted x 1) / (10 squares counted x 0.1µL) = cells per µL
Therefore, in this example:
(total cells counted) / (1µL) = cells per µL
1µL = 1 mm
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