Patent ID: 6890756

Claim:
A method of determining the hemoglobin content of a whole blood sample, the method comprising: a) combining a predetermined amount of the whole blood sample with a predetermined amount of a cyanide-free lyse solution to form a mixture, wherein the cyanide-free lyse solution includes: a quaternary ammonium salt surfactant, an anionic surfactant, a hemoglobin binding agent selected from the group consisting of imidazole and hydroxylamine, and an aqueous medium; b) developing the mixture to a molar absorbtivity (ε) in the range of about 12.4 to 12.6 mM −1 cm −1 , c) measuring a level of light absorbance of the mixture at a wavelength of about 540 nm, and d) calculating the hemoglobin content of the whole blood sample.