|Usage||Leukocytes, eosinophils and cerebro-spinal fluid cell counts|
|Ruling Pattern||Fuchs-Rosenthal (Dark-Line)|
Diluting fluid for counting cells in Cerebro-Spinal Fluid
|Crystal or Methyl Violet||0.2 gm|
|Glacial Acetic Acid||10 cc|
|Distilled Water||90 cc|
Collect about five CC. of spinal fluid in a sterile test tube containing a trace of Potassium Oxalate to prevent coagulation. The specimen should contain no visible trace of blood. Fill the capillary of a 1:10 pipette to the graduation with the diluting fluid and then draw the spinal fluid to the graduation above the bulb. Shake the pipette and charge the chamber as with blood corpuscle counting technique. Allow several minutes for settling.
The chambers are ruled with the Fuchs-Rosenthal pattern. This consists of 16 one square millimeter areas orientated by triple lines, and each such area sub-divided into 16 squares. It is generally recommended to count 16 one square millimeter areas preferably 8 in each chamber.
Calculating Formula if 16 one square millimeter areas were counted:
Number of cells counted X 10/9 = Cells per CMM
Note: For convenient calculation divide the cells counted by 3 instead of 3.2 and disregard the 10/9 dilution. The two fractions will compensate each other so that the remaining error will be negligible. If the entire ruled area of both cells was counted, divide the results of the above formula by two to obtain the cells per CMM.
After completing the count, remove the cover glass and clean the counting chamber with water or a mild cleaning solution (10% solution of bleach). Dry the counting chamber with a soft cloth or wipe, or rinse with acetone.