An Experimental and Theoretical Approach to Optimize a Three-Dimensional Clinostat for Life Science Experiments

Gravity affects all biological systems, and various types of platforms have been developed to mimic microgravity on the Earth's surface. A three-dimensional clinostat (3D clinostat) has been constructed to reduce the directionality of gravitation. In this report, we attempted to optimize a 3D clinostat for a life science experiment. Since a 3D clinostat is equipped with two motors, we fixed the angular velocity of one (primary) motor and varied it for the other (secondary) motor. In this condition, each motor ran constantly and continuously in one direction during the experiment. We monitored the direction of the normal vector using a 3D acceleration sensor, and also performed a computer simulation for comparison with the experimental data. To determine the optimal revolution for our life science experiment (i.e., a revolution yielding the strongest effects), we examined the promoter activity of two genes that were reported to be affected by microgravity. We found that the ratio of velocity of 4:1.8 (0.55) was optimal for our biological system. Our results indicate that changes of the revolutions of a 3D clinostat have a direct impact on the result and furthermore that the revolutions of the two motors have to be separately adjusted in order to guarantee an optimal simulation of microgravity.