Abstract: A chemiluminescent method is provided for the analysis of a target. A peroxidase is first bound as a labelling substance to the target by using a target specific binding reagent. The target so labelled is isolated and then reacted with luminol, hydrogen peroxide and an enhancer in an aqueous solvent. The luminescence of light is detected and measured. The aqueous solvent contains at least one protein selected from the group consisting of skim milk and egg albumin. Preferably, the aqueous solvent also contains a non-ionic surfactant such as a polyoxyethylene ether and/or a sugar alcohol such as mannitol.