TTC Nutrient Agar is widely used in microbiology for the cultivation and differentiation of microorganisms, particularly bacteria. The inclusion of triphenyltetrazolium chloride (TTC) allows for the visual identification of metabolically active colonies, as living cells reduce TTC to form a red, insoluble compound called formazan. This color change makes it easier to distinguish viable colonies from inert particles or debris on the agar surface.

It is commonly used in quality control testing in pharmaceuticals, food, and water industries to detect and enumerate aerobic bacteria. The medium supports the growth of a broad range of non-fastidious microorganisms, making it suitable for general microbiological testing. Its ability to indicate metabolic activity also makes it useful in assessing the effectiveness of disinfectants and antimicrobial agents, where the presence of red colonies clearly indicates surviving organisms.