Endo agar explained

Endo agar (also called Endo's medium) is a microbiological growth medium with a faint pink colour.^[1] Originally developed for the isolation of Salmonella typhi, it is now used mostly as a coliform medium. Most gram-negative organisms grow well in this medium, while growth of gram-positive organisms is inhibited.^[2] Coliform organisms ferment the lactose in this medium, producing a green metallic sheen (i.e. Escherichia coli), whereas non-lactose-fermenting organisms produce clear, colourless colonies, i.e. Salmonella species.

Typical composition

Endo agar typically contains (w/v):^[3]

• 1.0 % peptone
• 0.25 % dipotassium hydrogen phosphate (K₂HPO₄)
• 1.0 % lactose
• 0.33 % anhydrous sodium sulfite (Na₂SO₃)
• 0.03 % fuchsine
• 1.25 % agar

Notes and References

1. Web site: Mondofacto . 2009-04-25 . https://web.archive.org/web/20160303205734/http://www.mondofacto.com/facts/dictionary?Endo+agar . 2016-03-03 . mdy-all . dead .
2. Web site: Traditional Microbiology . 2006 . https://web.archive.org/web/20160303231139/http://www.bd.com/ds/productCenter/221167.asp . 2016-03-03 . mdy-all . 2022-11-28 . Becton, Dickinson and Co. (BD).
3. EMD Chemicals, Web site: ENDO Agar . 2002 . 2009-04-25 . dead . https://web.archive.org/web/20090413091223/http://www.emdchemicals.com/analytics/micro_manual/tedisdata/prods/1_04044_0500_5000.html . mdy-all . 2009-04-13.