A method for preparing five-part differential leukocyte analogs from red blood cells includes selecting appropriate red blood cells treating the red blood cells with a multi-functional reagent system for maintenance of a structural integrity of the membranes of the red blood cells and synchronous adjustment of cell volume, morphology and inclusions subjecting the treated red blood cells to an intensified fixation and washing the treated cells for preservation. The present disclosure also relates to leukocyte analogs prepared by the above method, a reagent system used for preparing the analogs, and a quality control and a calibrator including the analogs for use in a hematology analyzer.
