Peripheral blood film review - The demise of the eyecount leukocyte differential

Peripheral blood film review refers to checking or verifying flagged or abnormal results obtained by an automated hematology analyzer. This article discusses such issues as the: development of automated leukocyte differential instruments and the evolution of their use in the clinical laboratory; the rationale and justification of criteria established for slide review; elimination of proportional (percentage) differential results; the rationale for discontinuation of the 100-cell eyecount differential leukocyte count as part of the review process; and the role of restrictions of test requests to reduce the laboratory workload.