Manual determination of thrombocyte density from microscopic examination of stained blood films involves systematically counting these cells within a defined area of the slide and then extrapolating this count to a larger volume. For instance, a hemocytometer, though more commonly used for leukocyte counts, can also be adapted for this purpose. Alternatively, a specified area within a standard blood film can be used, though this method typically relies on correlating the observed platelet density with a concurrent automated count. Microscopic evaluation provides a qualitative assessment of platelet morphology, which can reveal clues about underlying hematological disorders.
This technique, while potentially less precise than automated methods, remains valuable in resource-limited settings, for educational purposes in hematology training, and as a validation tool for automated analyzers. Historically, before the advent of automated cell counters, microscopic examination was the standard method for quantifying platelets. Maintaining proficiency in this manual skill allows for critical evaluation of automated results and provides a backup method when automated systems are unavailable or malfunctioning. Furthermore, morphological assessment achievable through this method can be crucial for diagnosing specific platelet disorders that may not be detectable by automated counts alone.
