A "slow" temperature jump apparatus built from a stopped-flow machine.

A simple modification to a standard thermostated stopped-flow machine is described which allows it to be used as a temperature jump machine. Temperature jumps larger than 10 degrees C can be achieved in less than 150 ms which makes it useful for the range of times where conventional rapid temperature jumps are not applicable. The apparatus has a sample size of 300 microliters and can produce temperature jumps both above and below the initial temperature.