University of Turku shall procure two instrument: Stopped flow and quench flow instruments. Both instruments are intended to measure millisecond timescale kinetics of biochemical and chemical reactions. Stopped flow instrument is intended for monitoring the progress of reactions that lead to changes in absorbance or fluorescence of the reaction mixture. Two (or 3-4) solutions are rapidly mixed and the final mixture flows in an observation cell. When the flow is stopped, the kinetic is recorded with a spectrophotometer. Quench flow is the method for tracking the kinetics of non-optically active solutions. Two reagents are mixed, the mixture flows through a delay line at a defined flow rate to be aged and finally the reaction is stopped with a quencher solution. The concentrations of the reactants and/or products in the quenched reactions are then analyzed by the appropriate external (not related to the quench flow instrument) techniques. Other specific requirements are listed later and a tenderer is required to confirm those requirements are fulfilled.