Learning about Fluorescence in Undergraduate Biochemistry: Enzyme Kinetics Using a Low-Cost, Student-Built Fluorescence Spectrometer

Techniques and instrumentation that involve fluorescence are used in many careers related to biology and biochemistry. However, due to the expense of instrumentation, the theory and practice of fluorescence spectroscopy is commonly concentrated in instrumental analysis in most curricula, a class rarely required for biology and biochemistry majors. Biochemistry represents a course taken by these majors, providing an opportunity to expose them to the fundamentals of fluorescence. A three session laboratory series has been developed where the kinetic analysis of lactate dehydrogenase is carried out through the use of inexpensive, student-built fluorometers. These instruments are optimized for the detection of NADH fluorescence and constructed with interlocking building blocks (such as LEGO blocks), an LED source, a phototransistor detector, and other commercially available materials for a total cost of $52. Biochemistry students have built these spectrometers and used them to determine the Km of Gallus gallus lactate dehydrogenase for L-lactate and the kcat of this enzyme in accordance with literature values. Learning outcomes were assessed and indicate proficient understanding of instrument use and design.

Automated summary

A laboratory series has been developed using student-built inexpensive fluorometers for kinetic analysis of lactate dehydrogenase, providing biochemistry students with practical exposure to fluorescence fundamentals. Assessment of learning outcomes indicates proficient understanding of instrument use and design.