Kuroda K, Kamiya N
Department of Biology, Faculty of Science, Osaka University, Toyonaka,Japan.
Exp Cell Res. 1989 Sep;184(1):268-72. doi: 10.1016/0014-4827(89)90386-8.
Using the video centrifuge microscope we constructed, we observed the behavior of Paramecium cells in a solution of graded densities under centrifugal acceleration. Beyond 300g, they not only gather in the zone where the density is closest to theirs, but also orient themselves with their longitudinal axis parallel to the direction of centrifugation turning their anterior ends toward either centripetal or centrifugal direction. Since all of them retain still active swimming capacity, it is possible to calculate their propulsive force from the difference in density between theirs (1.04 g cm-3) and that of the upper or lower layer which they can reach. The propulsive force of single Paramecium cells thus obtained was calculated to be about 7 x 10(-4) dyn.
利用我们构建的视频离心显微镜，我们观察了草履虫细胞在离心加速下的梯度密度溶液中的行为。超过300g时，它们不仅聚集在密度最接近自身的区域，还会使自身纵轴与离心方向平行，将前端转向向心或离心方向。由于它们都仍保留着活跃的游动能力，因此可以根据它们自身（1.04 g/cm³）与它们能够到达的上层或下层密度差异来计算其推进力。由此获得的单个草履虫细胞的推进力经计算约为7×10⁻⁴达因。
