loading the sample (25 ml via the central feed) at the start
of the run and for displacement of the gradient for
collection of the samples at the end of the run. An overlay
(25 ml) of 90% DMSO was also used. After evacuation of
the chamber and acceleration of the rotor to 14000 rpm, at
20 8C a run time of 25 min was employed. After
deceleration of the rotor to 2000 rpm, ferrochemical oil
(FC43) of density r ¼ 1.9 g/ml (approximately) was
injected into the peripheral feed of the rotor chamber to
displace the fractions, which were collected in 24 tubes
(25 ml in each).