GENERAL CONSIDERATIONS

The ability of some bacteria to grow on media that are inhibitory to other bacteria gives the former organisms additional special characteristics that may help in their identification. The media themselves, with their selective and differential qualities, are of particular interest in diagnostic bacteriology and for this reason we have sometimes included a few notes on the isolation of certain bacteria and have referred occasionally to enrichment and other media used in culturing organisms from clinical material. We emphasize, however, that this Manual is concerned with how to identify organisms that have been isolated and not with how to isolate them.

In this appendix, media are listed under the following section numbers and headings:

1. A2.1 Basic media

2. A2.2 Enriched and enrichment media

3. A2.3 Differential and selective media

4. A2.4 Media for enhancing pigment production

5. A2.5 Media for carbohydrate studies

6. A2.6 Miscellaneous media

Cleaning and sterilization of glassware

Glassware for media such as Koser's citrate, in which there is a single source of an element such as carbon or nitrogen must be chemically clean to be free from it. A recommended method of ensuring this is to boil all tubes in 20% nitric acid for 5–10 minutes and then wash and rinse well with with glass-distilled water. Tubes are dried in an oven in the inverted position in baskets lined with filter or blotting paper to prevent the mouths of the tubes touching the metal.