In a leukocyte count using a hemocytometer, why is the sum of quadrant counts multiplied by 50?

In a leukocyte count using a hemocytometer, why is the sum of quadrant counts multiplied by 50?

• A. To account for dilution factor
• B. To convert to cells per microliter
• C. To average the counts
• D. To adjust for slide area

Answer: (B)

Leukocyte counting with a hemocytometer relies on knowing the exact volume you’re sampling. The cells you observe in the counted quadrants come from a defined, small volume of the chamber. To express how many cells there are in a standard unit of liquid, you convert that count to cells per microliter. The factor used in this conversion (50) is a fixed value that accounts for the chamber’s geometry, depth, and the dilution used when preparing the sample. Therefore, summing the quadrant counts gives you a total in a known volume, and multiplying by 50 yields the concentration in cells per microliter.

Leukocyte counting with a hemocytometer relies on knowing the exact volume you’re sampling. The cells you observe in the counted quadrants come from a defined, small volume of the chamber. To express how many cells there are in a standard unit of liquid, you convert that count to cells per microliter. The factor used in this conversion (50) is a fixed value that accounts for the chamber’s geometry, depth, and the dilution used when preparing the sample. Therefore, summing the quadrant counts gives you a total in a known volume, and multiplying by 50 yields the concentration in cells per microliter.