Alkaline Peptone Water is generally used as an enrichment medium in the isolation of Vibrio spp. from faeces. The high pH of the medium inhibits most enteric organisms for at least 24 hours. The medium is heavily inoculated with faeces and after not more than 8 hours incubation a loopful from the top of the medium is sub cultured onto TCBS Agar. This enrichment medium is also used for food and water testing.