Density gradient centrifugation (DGC) in Percoll for isolation and characterization of Oscillatoria spp. from Tjeukemeer

SUMMARY.

• 1 A high degree of separation was achieved in isolating Oscillatoria redekei and O. agardhii separately from Tjeukemeer seston by density gradient centrifugation (DGC) in Percoll. When diatoms were abundant, however, a pre-incubation in settling cyhnders was applied to obtain an optimal separation of O. redekei from diatoms.
• 2 One major band dominated by O. redekei was formed in the gradients. O. agardhii showed a varying distribution over three different bands and its banding pattern seemed to be related to the centrifugation resistance of its gas vacuoles and the turgor pressure.
• 3 Pigment ratios of O. agardhii were not affected by DGC in Percoll.