Development of standard materials for use with the hematofluorometer.

Two methods for preparing erythrocytes were evaluated for the purpose of developing stable, blood-based standard materials for the hematofluorometer. Erythrocytes washed with citrate-phosphate-dextrose solution and reconstituted with platelet-free plasma were stable for 12 weeks. Plasma-free erythrocytes washed with isotonic saline and resuspended in citrate-glycerol solution were stable for 18 weeks when stored at 4 degrees C. Consequently, plasma-free erythrocytes were successfully used as proficiency test specimens in the New York State Department of Health's Clinical Laboratory Evaluation Program for hematofluorometer users.