Tridodecylmethylammonium chloride, also known as TDMAC, is a cationic surfactant used widely in industrial and research settings. As a member of the quaternary ammonium compounds, it features a positively charged head and a hydrophobic tail, making it effective as a detergent, emulsifier, and antimicrobial agent. TDMAC is recognized for its ability to disrupt cell membranes and is frequently employed in microbiology for the selective isolation and identification of bacteria.