Method of analyzing nucleated red blood cells in a blood sample

A method of enumerating nucleated red blood cells in a blood sample comprising:

• (a) exposing a first aliquot of a blood sample to a first lysing reagent system to lyse red blood cells and to form a first sample mixture,
• (b) exposing a second aliquot of said sample to a second lysing reagent system to lyse red blood cells and to form a second sample mixture,
• (c) measuring said first sample mixture in a flow cell by a detection comprising a first direct current impedance measurement (DC1), radio frequency impedance measurement (RF), and light scatter measurement (LS),
• (d) measuring blood cell distributions of said second sample mixture by a second direct current impedance measurement (DC2) in a non-focused flow aperture,
• (e) analyzing blood cell distribution patterns obtained from measuring said first sample mixture, and differentiating nucleated red blood cells from other cell types,
• (f) analyzing blood cell distribution patterns obtained from measuring said second sample mixture, and differentiating nucleated red blood cells from other cell types,
• (g) performing a combined analysis on a profile obtained by combining results of analysis from step (e) and (f), said combined analysis further differentiating nucleated red blood cells from other cell types, and
• (h) reporting numbers of nucleated red blood cells per hundred white blood cells.