In the appropriate area of a well-made blood film, two to three white cells are seen per high dry field. The automated cell counter white count on the same patient is 20.6 ´ 109/L. Select the correct interpretation

a. The estimate matches the count; report the results.
b. The estimate does not match the count; investigate labeling error.
c. Repeat the estimate on oil immersion.
d. Rerun the sample through the cell counter.

ANS: B
The white count estimate from the blood film is 4 to 6 ´ 109/L. This does not match the obtained white count of 20.6 ´ 109/L. The most likely possibility of those listed is that this is a labeling error, and that the blood film is not from the same patient as the white count. This is considered a critical error.