A new "kinetic" method for enzyme analysis suitable for automation.

A method is proposed for automatic instrumentation of enzyme activity determinations which involve spectrophotometric measurements. The procedure utilizes a kinetic method to produce one instrumental reading that is proportional to enzyme concentration. The single spectrophotometric reading can be processed by analog or digital computation, using the known absorptivity constant of the reactant or product measured, to provide a value for enzyme activity expressed in micromoles of substrate consumed or product formed per unit time per unit volume under the specified conditions. Using the spectrophotometric measurement, one can establish enzyme concentrations based on absolute constants yielding results similar to those obtained by conventional kinetic measurements of zero-order reaction rates which are proportional to enzyme concentration.