Periodical contraction of a cultured muscle tube has been
measured with laser in vitro. C2C12 (mouse myoblast cell line)
was cultured with High-glucose Dulbecco’s Modified Eagle’s
Medium on a dish to make muscle tubes. Differentiation from
myoblasts to myotubes was induced with an additional horse
serum. Repetitive contraction of the tube was generated by
electric pulses lower than sixty volts of amplitude with one
milli-second of width through the electrodes of platinum, and
observed with a phase-contrast microscope. A laser beam of
632.8 nm wavelength was restricted to 0.096 mm diameter, and
applied to the muscle tubes on the bottom of the culture dish.
Fluctuating intensity of the transmitted laser beam through the
periodically contracting muscle tubes was measured, and its
spectrum was analyzed. The analyzed data show that the
repetitive contraction is synchronized with stimulation of the
periodical electric pulses between 0.2 s and 2 s.