K-SERIES CENTRIFUGES .2. PERFORMANCE OF K-2 ROTOR

Performance of the K-II continuous-sample-flow-with-banding zonalcentrifuge rotor was evaluated using sucrose gradients and polystyrene latex beads having a mean diameter of 0.091 μ and a banding density of 1.049 gm/cm3 in sucrose at 20°C. Narrower particle zones were recovered with static unloading as compared with dynamic unloading. With the former, the average band width at half-height was 64 ml in the total volume of 3600 cm3, corresponding, to a width of 0.24 mm in the rotor. Multiple reorientations of the gradient produced only a small loss of resolution. Measurements of gradient decay and sucrose loss during continuous flow indicate that gradients suitable for influenza virus recovery may be retained in the rotor for 10 hr, while 200 liters of fluid passes through the rotor. The particle capture efficiency of the rotor is slightly less than predicted by the Berman theory. © 1969 Academic Press, Inc.