Automated counting of nucleated red blood cells in blood samples of newborns.

Nucleated red blood cells (NRBC) in blood samples interfere with the white blood cell (WBC) count on many types of automated haematology analysers. This makes it necessary to correct the WBC count by counting NRBC microscopically. This report describes the evaluation of two analysers, the Cell-Dyn 4000 and the Sysmex XE-2100, which use new techniques to recognize and enumerate NRBC. We conclude that both the Cell-Dyn 4000 and the Sysmex XE-2100 give an accurate WBC count in the presence of NRBC. Furthermore, they can enumerate NRBC correctly when compared with microscopic observation.