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Protocol for Coulter Counter Z1 & Z2 Models
  1. Add 10 ml isoton to the cuvette containing 0.1 ml of your sample. Replace cuvette cap and invert a few times to mix.
  2. Lower platform of Coulter Counter and remove "blank" cuvette. Insert your sample and raise platform.
  3. The display should read "Analysis Result" and have a count from the "blank" sample. If so, you may press START. If not, please see the Trouble Shooting section below.
  4. You will hear the machine work as it counts your sample. When the counter is done, a number will be displayed. This calculation is only used if you use 10 ml of isoton and 0.1 ml of sample. If you perform a different dilution, you will need to adjust the calculation.
    The machine counts all the cells in 0.5 ml. 0.5 x dilution factor = # cells/ml in sample. To calculate how many cells you have, use the following calculation:
    200 x # on counter display = # of cells/mL
    200 x # on counter display x initial volume of sample = # of cells/sample
  5. Now lower platform and insert your next sample and repeat steps 3 and 4.
  6. When you have finished counting all of your samples, you must flush the machine! To do this, place the "blank" cuvette (contains isoton only) into the counter. Press FUNCTIONS. Use the left or right arrow keys until the display reads FLUSH APERTURE. Press START.
  7. When the machine is finished flushing, the display will read FLUSH COMPLETED. Now press SET-UP and then START and the machine will start counting the number of cells in the "blank" sample.
  8. If the count is below 50, you are done. If the count is above 50, you must flush the counter again. Pour out the isoton in the blank cuvette and replace it with 10 ml of fresh isoton from the dispenser. Repeat steps 6-8.


  • If display reads, FLUSH COMPLETED, press SET-UP and START to count the cells in the "blank" sample. Wait for the machine to finish counting the "blank" before you insert your sample. If the count displayed is above 50, please see step 6 for instructions on how to flush the counter.
  • If display reads CHECK DILUTENT VESSEL, you need to fill the bottle labeled "Dilutent" with clean isoton.
  • If display reads CHECK WASTE VESSEL, you need to empty the bottle labeled "Waste." The liquid can be poured down the drain.
  • If debris is clogging the aperture (visible through the Aperture Viewing Screen at the top right of the counter), find a member of the TCSR staff in W314 and we will unclog it for you.
  • If you experience any other problems with the Coulter counter, please see a member of the TCSR staff in W314 for assistance.
  • Do not change the settings on the Coulter counter! This may be convenient for you, but it is not for the next person who uses the machine!