Question

If the blood is diluted 1:100 and charged on the hemocytometer counting chambers on both sides, and the average platelet count from a counting chamber in one mm² (one large square) is 68, what is the calculated platelet count?

A. 680,000/mm³
B. 6,800/mm³
C. 68,000/mm³
D. 34,000/mm³

Answer 1

The calculated platelet count is 6,800/mm³.

Step-by-step explanation:

To calculate the platelet count, we need to use the dilution factor of 1:100. The average platelet count in one mm² of the counting chamber is 68. Since the chamber represents 1/100th of the total volume, we need to multiply the average count by the dilution factor. This gives us 68 * 100 = 6,800 platelets per mm³.

Answer 2

The observed platelet count of 68 in one large square is multiplied by the dilution factor (1:100) and then adjusted for both sides of the hemocytometer resulting in a calculated platelet count of 68,000/mm³.

So. the correct option is C.

Step-by-step explanation:

In the first step we start with the given information that the blood is diluted 1:100 and the average platelet count is 68 in one large square of the hemocytometer counting chamber. To calculate the actual platelet count we multiply the observed count by the dilution factor (1:100).

The calculation is as follows

68 (observed count) × 100 (dilution factor) = 6,800/mm³

However this is the count for one side of the hemocytometer. Since the question mentions counting chambers on both sides, we need to double this value.

6,800/mm³ × 2 = 13,600/mm³

Now taking into account the final dilution factor (1:100) we multiply the result by 100

13,600/mm³ × 100 = 1,360,000/mm³

Therefore the correct calculated platelet count is 68,000/mm³.

Hemocytometer: A specialized laboratory tool used for counting cells such as blood cells, under a microscope. It consists of a grid etched on a glass slide allowing for precise cell counting.