Detection of harmful chemicals and microbial pathogens in food and water destined for consumers is of importance the world over and new techniques and discoveries should be widely disseminated. This work presents research and a review of the established methods in this key area. Covering the four main areas of water microbiology, water chemistry, food microbiology and food chemistry, the book discusses highly sensitive chemical and biological detection systems. There are applications ranging from sample preparation methods to end detection. Subject areas include biosensors, the detection of pesticide residues, GM components, various chemicals and toxins as well as protozoan parasites and viral/bacterial pathogens in a wide range of materials.