Real-time temperature measurement of living cells exposed to microwaves using a temperature-dependent fluorescent dye

Abstract Real-time measurement of temperature in living cells exposed to microwaves is challenging because of the low spatial resolution of conventional temperature probes. Here, we established a noninvasive method by using a temperature-dependent fluorescent dye, Rhodamine B (Rho-B) to stain living cells that were exposed to a customized microwave exposure device. The relationship between Rho-B fluorescence and the temperature of living cells, and between Fluo4/AM and the inward inflow of Ca2+ were established. The results showed that the fluorescence intensity changed by 7.9% / °C as the temperature rose from 25 °C to 37 °C. The spatial resolution and temporal resolution of this method were 225×225 µm 2 and 1.5 s, respectively. In conclusion, the real-time temperature measurement technique is simple to use and requires no specialized equipment beyond a LSCM. This method can provide real-time information of the temperature changes in cells simultaneously with the investigation of calcium concentration.