Why hasn’t the automated blood cell counter totally replaced the blood smear?
It has on a routine basis, but the automated blood cell counter usually evaluates the RBCs, WBCs, and platelets based on their shape, size, and electrical or photometric properties. There can be some variation in each cell type and numbers the body produces due to a variety of physiological and external stimuli. Use of an automated instrument can often identify the presence of abnormal cells but lacks the ability to definitively subclassify them. Cell fragments and platelet clumps, particularly if they are large in size, can be mistakenly counted as WBCs, thus falsely elevating a white cell count. A laboratorian can see these abnormalities on a blood smear and has been trained to identify and classify them appropriately.
