Enzymatic reactions in microfluidic devices: Michaelis-Menten kinetics.
Kinetic rate constants for enzymatic reactions are typically measured with a series of experiments at different substrate concentrations in a well-mixed container. Here we demonstrate a microfluidic technique for measuring Michaelis-Menten rate constants with only a single experiment. Enzyme and substrate are brought together in a coflow microfluidic device, and we establish analytically and numerically that the initial concentration of product scales with the distance x along the channel as x5/2. Measurements of the initial rate of product formation, combined with the quasi-steady rate of product formation further downstream, yield the rate constants. We corroborate the x5/2 scaling result experimentally using the bioluminescent reaction between ATP and luciferase/luciferin as a model system.
Ristenpart
William D
WD
School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
Wan
Jiandi
J
Stone
Howard A
HA
D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D049454:Firefly Luciferin / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D049409:Luciferases, Firefly / Q000737:chemistry* / Q000378:metabolism; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D008956:Models, Chemical
D049454:Firefly Luciferin; D000255:Adenosine Triphosphate; D049409:Luciferases, Firefly