Intracellular Calcium Dynamics in ELF-EMF Exposure

The [Ca2⁺]_i was detected according to the previous study in our lab [30 (link)]. Briefly, the cells were seeded into poly-L-lysine-coated 96-well plates and exposed to ELF-EMF with and without the TRPC1-siRNA treatment in differentiation medium. After ELF-EMF exposure for 3 days, the cells were loaded with HEPES-buffered salt solution (HBSS) containing Fura 2-AM (5 μM, Dojindo, Japan) and 0.01% pluronic acid-127 (Sigma-Aldrich, USA) for 45 min at 37°C and then incubated in fresh HBSS for another 30 min to allow deesterification of the Fura-2 AM. Next, the cells were exposed to the 1 mT ELF-EMF for 30 min, and then the intracellular calcium was immediately measured using an Infinite M200 Microplate Reader (TECAN, Austria). The excitation wavelength was set at 340 nm and 380 nm, respectively. The fluorescence emission was monitored at 510 nm. The ratio of the fluorescence intensity at 340 nm to that at 380 nm was calculated to represent the peak amplitude of [Ca²⁺]_i.