Washing solution for solid-phase immunometric methods which contains stabilizers for the labeling system, and the use thereof

A method for determining the amount of an analyte in a sample of a biological fluid, wherein said method is carried out by an instrument and comprises the following steps

• a) fixing a first antibody specific for said analyte to a solid phase;
• b) bringing said sample into contact with said immobilized first antibody;
• c) incubating analyte bound to said first antibody immobilized on said solid phase with a second antibody specific for said analyte, which second antibody carries an enzyme as label, wherein said enzyme is selected from the group consisting of peroxidase, alkaline phosphatase and β-galactosidase;
• d) washing said solid-phase with a washing solution where said washing solution contains phenol or a phenol derivative carrying one or more substituents, wherein said substituents are C1 to C3-alkyl groups, chlorine or bromine atoms;
• e) removing said washing solution;
• and
• f) determining the amount of label bound to said solid-phase.