Rapid bacteria test

A method for quantitatively determining bacteria in a sample, comprising the steps of:

• (a) incubating the sample to be tested together with a labelling reagent that can bind to the bacteria to be determined in a measuring cell comprising a first and a second chamber, wherein the labelling reagent is a labelled bacteriophage, wherein said sample is incubated in the first chamber of said measuring cell,
• (b) removing labelling reagent that has not bound to the bacteria from the bacteria by means of a membrane arranged between the first and second chamber, wherein said membrane is impermeable to the bacteria to be determined and is permeable to the labelling reagent that is not bound to the bacteria to be determined, wherein the bacteria to be determined are collected on the membrane and said labelling reagent that has not bound to the bacteria is moved into said second chamber,
• (c) detecting the labelling reagent bound to the bacteria collected on said membrane, and
• (d) quantitatively evaluating the measurement signal from step (c), wherein the quantitative evaluation of the measurement signal comprises a calibration by using an internal standard.