The platelet count from the automated cell counter is 80 109/L. ...

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The platelet count from the automated cell counter is 80  109/L. Platelet satellites around neutrophils are observed on the blood film estimate. A sodium citrate tube is drawn, and the count reads 300  109/L from the cell counter.
 
  What platelet count  109/L should be reported?
 
  a. 80
  b. 300
  c. 330
  d. The estimated count from the blood film

Question 2

Why is it important to have a scrupulously clean hemocytometer when manually counting platelets?
 
  a. So few platelets exist that they can be missed if dirt is present.
  b. They are so refractile, they can be confused with dirt.
  c. Their small size makes them easily confused with dirt.
  d. They are easily confused with the red cells that are present.

[snackralk]

Answer to Question 1

ANS: C
The platelet count from the automated cell counter cannot be accepted because it is falsely low because of the platelet satellites seen on the blood film. This is an occasional problem in some patients when their blood is drawn in ethylenediaminetetr aacetic acid (EDTA). Drawing the blood into sodium citrate eliminates the satellites. However, this tube results in a dilution of the blood (nine parts blood plus one part anticoagulant = 9:10 dilution of blood). The platelet count from the instrument must therefore be multiplied by 1.1 (= 10/9) to obtain the valid platelet count. Therefore the platelet count = (300)  (1.1) = 330 ( 109/L).

Answer to Question 2

ANS: C
Platelets are small and can be easily confused with dirt, thus invalidly increasing the platelet count.