SEDIMENTATION-VELOCITY OF LOXODES STRIATUS IMMOBILIZED BY MNCL2

The sedimentation of Loxodes striatus was determined for g-values betw een 1g and 5g employing a new method of immobilization by MnCl2, and u sing a low-speed centrifuge microscope to induce hypergravity. Cells i mmobilized by MnCl2 can be used for at least 4 hours compared to 30-60 minutes after common immobilization in solutions of NiCl2. The sedime ntation rates of Loxodes, as determined from the medians of several hu ndred cells, agree with published values of NiCl2-immobilized cells. T he sedimentation velocities between Ig and 2g are fitted by a linear r egression line resulting in an extrapolated rate of 42 mu m/s at 1g. D eviations of the measured values from this linearity at higher acceler ations are explained by a methodical experimental variable assuming th at proportionality between sedimentation rate and acceleration is appl icable according to Stokes' law.