The Coulter Counter leukocyte differential

The leukocyte differential counting capability of the Coulter Counter model S-PLUS IV was evaluated for precision, accuracy, and clinical sensitivity. The evaluation used procedures described in the NCCLS tentative standard (H20-T) when these were appropriate for this technology. Within its inherent constraints, the system was found to be more reproducible than the stained-film reference method and at least as accurate. Clinical sensitivity was equivalent to that of a four-slide, microscope differential count. Reference ranges for the cell classes identified by the instrument were similar to those given by the stained-film method.