Conventional stopped-flow systems are usually limited to -15°C/-20°C because of the materials used in valves and driving syringes. However, some chemical reactions are still too fast to be observed at these sub-zero temperatures. One solution to elucidate the reaction mechanism is to slow down the reaction. By reducing the reaction temperature to -90°C the reaction becomes about 10,000 times slower when compared to ambient temperature, meaning that some events become observable. Cryo stopped-flow covers temperature ranges below -15°C where traditional stopped-flow experiments are limited. Cryo stopped-flow instruments are now well-established systems in inorganic and bio-inorganic chemistry laboratories where they have proved to be efficient tools used to identify reaction intermediates and define reaction mechanisms.

Cryogenic option down to -90°C.
The cryogenic option extends the range of Bio-Logic stopped-flow to -90°C. It is available for single and double mixing applications. The mixers, the cuvette and the transfer lines are immersed in a cryo-solvent.  Two cooling methods are available for the cryo bath: using liquid N2 circulation or using a commercial cryostat. Temperature dependence studies can be carried out from -90°C to +20°C without any reconfiguration. The mixing chamber is connected to the detection system using fiber optics and spectra can be recorded every 400 µs using our fast diode array detectors to fully benefit from the 2ms dead time.