Evaluation of an 8-color flow cytometric reference method for white blood cell differential enumeration.

Background: Manual microscopy is the current reference method for white blood cell (WBC) differential counts. However, manual counts are time and labor intensive, difficult in patients with low WBC counts, and can misclassify cells having difficult morphology. We investigated an 8-color, single-tube, lyse no-wash flow cytometric method to perform an extended 8-part differential as a potential replacement reference method for WBC differential enumeration.