The API 20E test is used to identify Enterobacteriaceae bacteria based on their biochemical and metabolic activity. The API 20E strip contains 20 microtubes with dehydrated substrates that are reconstituted when a bacterial suspension is added. As the bacteria incubate and react with the contents of the tubes, their metabolites cause color changes in various indicator systems, allowing identification based on the pattern of reactions.

1. Analytical
Profile Index
20E

2. API 20E
Standardised identification for Enterobacteriacae.

3. • Bacteria Spp. Is identified based on the biochemical & metabolic activity of
the bacteria
• The API 20E strip contains 20 microtubes, each containing dehydrated
substrates. The substrates are reconstituted by adding a pure bacterial
suspension.
• They are incubated and the bacteria react with the contents of the tubes
• The various indicator systems are affected by the metabolites resulting in a
colour change.

5. API20E after innoculation
Nitrogen metabolisms and specific enzymes Carbohydrate metabolisms

6. IMPORTANT
• Create anaerobiosis in ADH LDC ODC H2S URE by overlaying
bacterial suspension with mineral oil
• Completely fill both the cupule and tube of CIT VP GEL
• Only fill the cupule of the other tests

7. For the purpose of this lab consider all bacteria oxidase negative