The identity of an organism may be confirmed by demonstrating its ability to perform a number of biochemical reactions, each species conforming to a recognizable result pattern. Most of the media used in the tests detailed in this section can be obtained from commercial sources | 10 Confirmatory biochemical tests Acid production from sugars CAMP test Catalase production Coagulase test Desoxyribonuclease production Gram reaction Haemolysis Hippurate hydrolysis Hydrogen sulphide test Indole test Motility test Nitrate reduction O129 sensitivity Oxidase test Spore stain Urease test Voges Proskaüer test The identity of an organism may be confirmed by demonstrating its ability to perform a number of biochemical reactions each species conforming to a recognizable result pattern. Most of the media used in the tests detailed in this section can be obtained from commercial sources usually in powder form and require reconstituting and sterilizing before use. Some of the reagents prescribed in the tests may not be available commercially and so methods for the preparation of these have been included in this section. This section does not cover the entire range of biochemical and other identification tests encountered in food microbiology but it brings together a number of those most commonly used and a few which are specific to a particular group of organisms. Rapid multi-test micro-methods as discussed briefly at the start of Section 6 are not included. A fuller range of identification tests can be found in Cowan and Steel s Manual for the Identification of Medical Bacteria 1 . Positive and negative controls should be included in each batch of tests. The reference strains of control organisms are listed in the test methods where appropriate. Acid production from sugars 1 Examples of sugars include glucose salicin mannose xylose and rhamnose. Confirmatory biochemical tests 243 Control organisms Control organisms for sugar reactions may vary according to individual laboratory preference. Stock cultures should be kept of organisms that have known positive and negative reactions in each sugar. Reagents Peptone water 1 peptone NaCl 10 sugar solutions .
