Functional weightlessness during clinorotation of cell suspensions

A clinostat is a device often used in gravitational biology studies. Selecting an appropriate speed of rotation, however, is a frequently,debated topic, particularly for suspended cells. In an attempt to define the necessary criteria for determining an acceptable revolution speed, the primary forces governing particle behavior during clinorotation - gravity, diffusion and centrifugation - were mathematically assessed. In support of the theoretical exercise, bacterial growth experiments indicated that results obtained using a clinostat followed trends resembling previous space flight results. It is suspected that this is due, in part at least, to similarly altered external transport processes in each environment. (C) 1998 COSPAR. Published by Elsevier Science Ltd.