An automatic apparatus for the study of enzyme kinetics.

A continuous-flow apparatus is described for automatically plotting substrate saturation curves, and is suitable for use with a variety of enzymes. A linear concentration gradient of the variable substrate is combined with a fixed proportion of the other substrates and the enzyme, and after passing through a reaction coil the product concentrations are measured spectrophotometrically. Use of a 4cm. flow cell and modified spectrophotometer permits accurate measurement of NADH concentration in the region of 0.1mum. Precise control over reaction times and substrate concentration is achieved by using power-driven syringes with an integral mixer. Specimen results are given for yeast alcohol dehydrogenase.