When performing WBC differential, at what magnification should you count 100 WBC?

When performing WBC differential, at what magnification should you count 100 WBC?

• A. 40x
• B. 100x
• C. 10x
• D. 400x

Answer: (B)

Counting 100 white blood cells in a manual WBC differential is done at high power to balance detail with an adequate sample size. The standard practice uses a magnification of about 400x total, which comes from a 40x objective combined with a 10x ocular. This level provides enough resolution to distinguish different leukocyte types—such as recognizing nuclear shape and cytoplasmic features—while allowing a sufficient field of view to sample a representative number of cells in a reasonable time. Using lower magnification would give too few details to reliably identify cell types, and using higher magnification (like oil immersion) would narrow the field too much and make counting 100 cells inefficient. So, count 100 WBCs at high power, around 400x total magnification.

Counting 100 white blood cells in a manual WBC differential is done at high power to balance detail with an adequate sample size. The standard practice uses a magnification of about 400x total, which comes from a 40x objective combined with a 10x ocular. This level provides enough resolution to distinguish different leukocyte types—such as recognizing nuclear shape and cytoplasmic features—while allowing a sufficient field of view to sample a representative number of cells in a reasonable time. Using lower magnification would give too few details to reliably identify cell types, and using higher magnification (like oil immersion) would narrow the field too much and make counting 100 cells inefficient. So, count 100 WBCs at high power, around 400x total magnification.