What is the total volume of one side of a hemocytometer if the ...

[futuristic]

What is the total volume of one side of a hemocytometer if the ruled area is 3  3 mm and the depth is 0.1 mm?
 
  a. 0.3 mm3
  b. 0.9 mm3
  c. 1.0 mm3
  d. 9 mm3

Question 2

Which of the following would cause a manual cell count to be falsely high?
 
  a. Unopette not mixed before charging the hemocytometer
  b. Not wiping excess blood from outside of pipette when filling
  c. Using a smaller volume pipette than that specified by the Unopette system
  d. Pulling blood out of the pipette when wiping away excess on the outside

[kishoreddi]

Answer to Question 1

ANS: B
Volume = area  depth = (3  3)  0.1 = 0.9 mm3

Answer to Question 2

ANS: B
Blood left on the outside of the pipette will add to the blood in the pipette when the pipette tip is placed in the Unopette reservoir. This will increase and invalidate the cell count (falsely high). If the Unopette was not mixed before charging, then the count would most likely be low. Pulling blood out of the pipette when wiping away the excess on the outside will falsely lower the cell count because less blood will be present. Using a smaller volume pipette than required will lower the count, again because less blood will be present.