Abstract: This invention relates to lytic reagents and methods of using the lytic reagents for automatically determining leukocyte subpopulations in blood. More specifically, the new lytic reagents selectively lyse red blood cells and certain leukocyte subpopulations, which enables the differentiation of at least one subpopulation of leukocytes. The lytic reagents contain an ethoxylated long chain amine, a quaternary ammonium salt and an acid. When used in combination with a second lytic reagent system, one is able to obtain at least a five part differential of leukocytes by impedance and light scatter measurements, by impedance and radio frequency measurements, or by radio frequency and light scatter measurements.

Abstract: An improved isotonic multipurpose blood diluent, and a method for use of this diluent is provided. The diluent is especially suitable for electronic enumeration and sizing of blood cells, determination of hemoglobin parameters and differentiation of leukocyte subpopulations in a single blood cell sample using a cyanide free lytic reagent. The diluent finds particular applicability over wide operating temperatures.

Abstract: A reagent composition which does not contain cyanide ions and a method for measuring hemoglobin concentration in a blood sample. In addition, the reagent composition can be used to measure hemoglobin concentration and differentiate at least two subpopulations of leukocytes from the same reaction product of the reagent composition and a blood sample. The reagent composition comprises at least one lysing agent selected from the group consisting of a quaternary ammonium salt, a pyridinium salt, and combinations thereof, in an amount effective to adequately lyse the erythrocytes and elute the hemoglobin, an antioxidant in an amount effective to convert the released hemoglobin into to a hemochromogen. The pH can be adjusting with a pH agent to provide a pH ranging from 5 to 11.5.