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 K
m of Gallus
gallus lactate dehydrogenase for L-lactate and the k
cat of this enzyme in accordance with literature
values. Learning outcomes were assessed and indicate proficient understanding
of instrument use and design.