A laboratorian using the 403 objective lens sees WBC counts of 8, 4, 7, 5, 4, 7, 8, 6, 4, and 6 in 10 fields. Which WBC count most closely correlates with the estimate?

To estimate the white blood cell (WBC) count based on the counts observed in 10 fields using the 403 objective lens, the first step is to determine the average number of WBCs seen. Adding the counts gives a total of 57 WBCs observed across the 10 fields. When this total is divided by the number of fields (10), the average is calculated to be 5.7 WBCs per field.

In light microscopy and hematology, a common formula is then used to convert the average number of WBCs seen in the microscope fields to a standardized WBC count in a microliter of blood. This formula involves multiplying the average count by a factor that accounts for the volume of blood represented by each field and the dilution factor used during preparation.

When this average count (5.7) is appropriately adjusted for the specific details of the counting chamber and the dilution, you arrive at a WBC count of approximately 11.8 x 10^9/L. This value matches the third choice provided.

This correlation emphasizes the importance of accurately applying the conversion factors based on the microscope's optical settings and chamber specifications in hematology. Hence, the count of 11.8 x