MacConkey Broth is used for the detection of coliform organisms in milk and water.

• Peptone provides amino acids and other growth factors
• Lactose is a carbon energy source
• Oxgall inhibits the growth of gram-positive organisms
• Bromcresol purple is the indicator

MacConkey Broth is a modification of the original bile salt broth recommended by MacConkey that contained 0.5% sodium taurocholate and litmus as an indicator.