The goal of this laboratory exercise is to give upper-level undergraduate students an introduction to sterile technique in mammalian cell culture and metabolism. The experiment can be completed within a 3-h lab period and can be performed either in conjunction with other biochemistry/metabolism experiments or used as a stand-alone experiment. In this experiment, students are tasked with relating the acidification of cell culture medium to metabolism in order to elucidate the mechanism of action for a compound. Students can relate their experimental results to topics covered on glycolysis and oxidative phosphorylation in upper-level biochemistry classes as well as gain valuable experience relating metabolism to drug discovery.