A blood film for a very anemic patient shows an average of seven platelets per oil immersion field. What value most closely correlates with this estimate per microliter?

To determine the correlation between the observed average of seven platelets per oil immersion field and the platelet count in microliters, it’s essential to understand how platelet counts are usually evaluated in a laboratory setting.

In a typical blood film examination using an oil immersion lens, one can estimate the number of platelets per microliter based on the number counted per field. The formula often used is roughly estimating that the number of platelets per field should be multiplied by a conversion factor, typically around 15,000 to yield the total count in microliters.

When you observe an average of seven platelets per field, multiplying by this conversion factor gives:

7 platelets/field × 15,000 fields/µL = 105,000 platelets/µL

However, different laboratories and methods may use slightly different factors, and a practical approach often used for more accurate estimation might lead to adjustments in the final number.

In this scenario, the option that most closely correlates with the estimate of seven platelets per oil immersion field aligns with a count near 44,000 platelets per microliter, which would suggest a more conservative approximation when considering variations in techniques and other factors in the estimation process. This number represents