Reticulocyte quantification by Coulter MAXM VCS

In this study the ability of the Coulter MAXM analyzer to quantify reticulocytes was evaluated. The results were com-pared with those obtained by a microscopic method accord-ing to NCCLS H44-P recommendations and with the results from the automated analyzer Sysmex R-1000. Du-plicate samples from 330 patients were analyzed. The reference intervals obtained with the three methods were: MAXM 0.37-1.80%, median 0.83%; manual 0.40-2.30%, median 1.00%; R-1000 0.60-1.95%, median 1.06%. The imprecision (CV) at all concentrations is lower than the microscopic method (low 16.1 % vs 67%; normal 16.9 % vs 28.9%; high 9.5 % vs 13.0%). The MAXM shows a good overall correlation with the microscopic method (intercept 0.01, slope 0.89, r = 0.87) despite evidence of a significant overestimation at low concentrations [difference (D) 0.30