hown below is an image of a peripheral blood film as seen us

hown below is an image of a peripheral blood film as seen using the 40x objective. If you examined 10 similar fields of view, then what is the average neutrophil count? Assume the FOV of the 4x objective has a diameter of 6 mm.

Solution

Answer: The ratio of low to high power is 0.4/4. So at high power you will see 0.4/4 of the low power field of view (6 mm). 0.4/4 x 6 = 0.1x6 =0.6 mm.

The total number of peripheral blood cell will be calculated as

0.4/4x10= 0.1x 10= 1#

The average number of neutrophil cell will be 1.