Application of laser to measurement of cyclic contractile movement of cultured myotubes

Laser technique has been applied to measure cyclic contractile movement of cultured myotubes in vitro. The designed measurement system includes light source (helium neon, 632.8 nm wave length), charge-coupled devise cameras and detectors. Cyclic contraction of myotubes cultured from C2C12 (mouse myoblast) was generated by cyclic electric pulses (amplitude < 60 V, 1 ms width) through electrodes of platinum wire dipped in the medium. The spectrum of fluctuating intensity of the transmitted laser beam through the myotubes, which periodically repeated contraction and relaxation, was analyzed. The results show that the designed laser system is effective to detect frequency of cyclic contractile movement of myotubes between 0.5 Hz and 5 Hz.