Presence-Absence Broth Ampules, 25/pk

Presence/Absence Broth ampules provide an easy-to-use test, ideal for screening drinking water samples for the presence of total coliform bacteria. Simply combine the P/A broth with your 100mL sample and incubate for 24 to 48 hours at 35 degrees Celcius. A color change to yellow or yellow brown indicates presence of coliform bacteria.