Used in microbiology to identify bacteria based on their ability to utilize citrate as a sole carbon source. It helps differentiate Enterobacteriaceae species, especially in distinguishing Salmonella and Klebsiella, which typically produce a positive result (color change to blue), from Escherichia coli, which usually gives a negative result (no color change). The medium supports the growth of organisms that can metabolize sodium citrate, and the pH indicator detects alkaline byproducts of citrate metabolism. Commonly used in clinical labs for stool culture workups and in food and water testing to characterize bacterial isolates.