An automated method for measuring the development of a biofilm, containing one or more fluorescent moieties, on a plurality of surfaces using a confocal imaging system including: a) a radiation source system for forming a beam of electromagnetic radiation including one or more wavelengths; b) an optical system for directing and focusing said beam onto one or more planes of the object; c) a detection system for detecting electromagnetic radiation emitted from the object and producing image data; and d) a scanning system for scanning the object in a plurality of planes with the electromagnetic radiation, the method comprising the steps of: i) growing said biofilm on said plurality of surfaces; ii) detecting the presence of said one or more fluorescent moieties within the biofilm by scanning the biofilm with electromagnetic radiation in a plurality of planes and collecting fluorescent emissions to produce a plurality of images; and iii) analysing said images by means of a data processing system under the control of computer software to determine the structure of the biofilm.