Fingerprinting becomes more exact, less time consuming, less subjective, and less expensive than culturing and special laboratory sample manipulations. Due to impending health concerns and the need for cost controls, rapid microbial fingerprinting methodologies have become desirable. The methods of greatest interest to the environmental professional are the Polymerase Chain Reaction (PCR) and the Microbial Identification System. The PCR process is highly specific and extremely sensitive in its ability to differentiate biological systems through the uniqueness of their deoxyribonucleic acid (DNA)/genetic blueprinting. The PCR process has been proven particularly useful in responsing to outbreaks of Legionnaires' disease. The PCR process identifies and quantitates "viable, disease-causing" and "nonviable, nondisease-causing" microbes as well. The correlation between total count of disease-causing and nondisease-causing versus disease-causing cultural counts is unclear. The pathogenic microbes pose a life threatening problem for which solutions may involve life and death situations. Yet, there are uses for non-pathogenic bacterial fingerprinting as well.