The sucked-flow analyser: a simple apparatus for automatic determinations of steady-state enzyme kinetics

The sucked-flow analyser is a modified stopped-flow apparatus for automatic measurements of initial rates of enzyme reactions at varying concentrations of substrate or inhibitor. The flow through the system is driven by a water suction pump and regulated by magnetic valves. Sample and reagent solutions are aspirated through tubes whose resistances to laminar flow determine a precise ratio of mixing in the observation cell. A minicomputer controls all operations, collects the data and calculates the results. Measurements on the beta-galactosidase and the cytochrome P-450 reactions are presented.