Logarithmic timebase for stopped-flow data acquisition and analysis.

A method for capturing stopped-flow and other rapid reaction records in logarithmic time, using a microcomputer, is described. Apart from the ability to record processes over several decades in time in a single experiment, the method shows distinct advantages in subsequent nonlinear regression analysis of multiexponential processes. The method is illustrated by a study of the binding of NADPH to dihydrofolate reductase and the reaction between formycin triphosphate and heavy meromyosin.