Patent ID: 7235404

Claim:
A cyanide-free lytic reagent composition comprising an aqueous solution of: (i) a quaternary ammonium surfactant, represented by following molecular structure: wherein R 1 is an alkyl, alkenyl or alkynyl group having 10 to 18 carbon atoms; R 2 , R 3 and R 4 are alkyl groups having 1 to 4 carbon atoms and X − is chloride or bromide; and said quaternary ammonium surfactant is in an amount sufficient to lyse red blood cells and release hemoglobin; and (ii) a ligand in a sufficient amount to form a stable chromogen with said hemoglobin selected from the group consisting of: (a) oxalic acid, (b) malic acid, (c) malonic acid, (d) ethylene diamine, (e) N,N-diethylethylene diamine, (f) N,N′-diethylethylene diamine, (h) diethylene triamine, (i) tetraethylene pentamine, (j) 1,6-hexanediamine, (k) 1,3-pentanediamine, (l) 2-methylpentamethylenediamine, (m) 1,2-diaminocyclohexane, (n) 4-aminoacetophenone, (o) bis-hexamethylenetriamine, (p) pyridazine, and (r) 3,6-dihyroxypyridazine; wherein pH of said lytic reagent composition is in a range from about 3 to about 10.