Cultures for Bioassay

Micro-organisms are frequently supplied as freeze dried cultures in vacuo in sestled ampoules. Instructions for dealing with these are given in Chapter 3. 

Bacteria used for assays can be divided into two groups, spore formers and non-spore formers. The genus Bacillus, which are spore formers, are the most commonly used organisms for microbiological assay. 

Assays using non-sporulating species Escherichia coli or Micrococcus luted) require cultures to be prepared before they are needed for the assay. This is done by growing the organism on an agar slope overnight, and washing it off with sterile 

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