MacConkey Agar | 合法醫療器材資訊網

MacConkeyAgar.Thismediumisbothselectiveanddifferential.Theselectiveingredientsarethebilesaltsandthedye,crystalvioletwhichinhibitthegrowthof​ ...

This medium is both selective and differential. The selective ingredients are the bile salts and the dye, crystal violet which inhibit the growth of Gram-positive bacteria. The differential ingredient is lactose. Fermentation of this sugar results in an acidic pH and causes the pH indicator, neutral red, to turn a bright pinky-red color. Thus organisms capable of lactose fermentation such as Escherichia coli, form bright pinky-red colonies (plate pictured on the left here). MacConkey agar is commonly used to differentiate between the Enterobacteriaceae.