To obtain a solution which can clean the surface of an apparatus in a manner, avoiding the accumulation of residues on the surface by constituting to include a process, in which the apparatus is brought in contact with an aqueous compound including a quaternary ammonium salt or quaternary phosphonium salt expressed by a specific formula.
This cleaning solution contains a quaternary ammonium salt and/or a quaternary phosphonium salt, expressed by the formula (wherein R1 is a 7-24C alkyl of a direct chain or branched chain type; R2, R3 and R4 are 1-4C lower alkyls; X+ is an N or P; and Y is an anion, e.g. Cl, Br or HSO4. The alkyl group may be substituted with a soluble group, e.g. OH or CO2H.). These salts are effective in solving the problem of carry-over leukocyte at a concentration to be low so as not to interfere with the liquid level sensor of an analyzing equipment. Moreover, since the quaternary ammonium and/or phosphonium salt characterized in the formula is used, adverse effects due to a clearness of an optical face are reduced significantly.
BLOCZYNSKI MICHAEL L
FARR JENNIFER
