Controlling feeding gas temperature of plasma jet with Peltier device for experiments with fission yeast

The suitable temperature condition for fission yeast growth is around 30 degrees C, whereas the gas temperature of commonly used atmospheric pressure helium plasma jets tends to increase with discharge time. To avoid the damage of fission yeast from heat, a Peltier device was used to control the feeding gas temperature of low-frequency helium plasma jet. The temperature of a thermistor directly irradiated by the plasma jet plume remained almost constant at the acceptable temperature to fission yeast for more than 200 s. The morphology of fission yeast cells exposed to the gas-temperature-controlled plasma jet plume was examined. Some of the cells in the proximal of the plasma irradiation point showed elongated shape, which is not seen in wild-type fission yeast cells under normal conditions. (C) 2019 The Japan Society of Applied Physics