[The progresses in the determination of blood monocytosis and its perspectives of clinical application in pathology].

Automated cell counters have allowed the reproducible analysis of the 5 leucocyte populations (neutrophils, eosinophils, basophils, lymphocytes and monocytes). Determination of the monocyte count by classical microscopic analysis can be inaccurate. We have compared the automated monocyte count from the coulter STKS (program 1F) with counts obtained by microscopic analysis of 1000 leucocytes and by flow cytometric analysis of cells stained simultaneously with a pan-leucocyte and a monocyte-specific antibody. The values provided by the coulter STKS are sufficiently precise to recommend the routine clinical use of this automated counter.