| abstract |
A cyanide-free lytic reagent composition and method for measuring the total hemoglobin concentration in a blood sample, for counting the number of leukocytes and for deferential counting of leukocyte subpopulations are described. The cyanide-free lytic reagent composition cotains a quaternary ammonium salt or a pyridinium salt to lyse erythrocytes and release hemoglobin, and an organic ligand including triazole and its derivatives, tetrazole and its derivatives, alkaline metal salts of oxonic acid, melamine, aniline-2-sulfonic acid, quinaldic acid, 2-amino-1,3,4-thiadiazole, triazine and its derivatives, urazole, DL-pipecolinic acid, isonicotinamide, anthranilonitrile, 6-aza-2-thiothymine, 3-(2-thienyl)acrylic acid, benzoic acid and alkali metal and ammonium salts of benzoic acid, and pyrazine and its derivatives to form a stable chromogen with hemoglobin, and a salt to adjust conductivity of the reagent for impedance measurement. The reagent composition is mixed with a blood sample without pre-dilution and the UV absorption of the sample mixture is measured at the predetermined absorption wavelength. Counting the number of leukocytes and differential counting of leukocyte subpopulations are accomplished simultaneously on an automated cell counter utilizing DC impedance measurement. |