Microbiology lab media plates show E. coli bacteria growing on E. coli selective agar (pink) and blood agar (red). Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news ...

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 ...