Abstract: A method for quantitative and/or qualitative determination of germs in a liquid sample comprises the steps of: (1) passing the sample through a filter thereby depositing the germs on a major portion of the filter so that a minor portion of the filter is free of germ deposits; (2) applying a fluorescent label to at least a portion of the deposited germs; (3) determining the presence and/or the amount of labeled germs by fluorescent reflection photometry. The method according to the present invention is suitable, for example, for quantitative and/or qualitative determination of germs in foodstuffs, surfactant-containing products such as washing and cleaning agents, surface treatment agents, dispersion products, cosmetics, hygiene products and personal care products, pharmaceuticals, adhesives, coolant lubricants, coatings and coating coagulations, as well as raw materials and starting materials for the aforesaid products.