Effect of a microwave warming of cell culture media on cell viability and confluence rate

Here we present a method for rapidly and stably warming up a small volume of cell culture media that can maintain cell viability and confluence rate. This method uses microwave radiation for warming without any direct contact with water, preventing the potential issue of contamination induced by the use of a water bath. To demonstrate the proof of concept validation, we used a conventional microwave oven for warming cell culture media. In our experiments, it took only 10 s to warm a 50 mL-media tube (mostly proper volume for the use of microfluidic cell culture experiments) up to 37 °C. Multiple tubes can also be used to increase the volume of cell culture media by placing them in a plastic support within the oven at the same time in a scalable manner. The results show that there was no jump discontinuity to a higher temperature than 37 °C within 10 s. Both apoptosis and necrosis were monitored and examined to confirm whether the new method can affect cell viability and metabolism. The proposed method is fast, easy and user-friendly in conventional cell culture process, even scalable for the use of large media volume, and free of biological contamination due to water contact occurred by use of conventional water baths. We furthermore believe that this approach can be potentially helpful for advancing on-chip cell culture process that may require a small volume of cell culture media often used in microfluidic devices.