Centrifugation swinging bucket rotors

Desk top clinical centrifuges (swinging bucket rotor)... 

Spin in clinical centrifuge (swinging bucket rotor) at room temperature to concentrate phases. We use setting 7 on our lEC clinical (around 6,000 x g) for 10 min. 

Fig. 11. (a) Diffeiential centrifugation (pelleting), where time 1 < time 2 < time 3 < time, (b) Rate 2onal separation in a swinging-bucket rotor, where tube 1 represents the density gradient solution, tube 2 the sample plus the gradient, and tube 3 the separation of sample particles under a centrifugal force, where... 

Step 1. Load a disposable mini-chromatography col-umn with Sephadex G-50 (fine) dextran that was previously permitted to equilibrate with 5 volumes of the desired new buffer. Allow all the liquid to drain under the earth s gravitation to leave a 1 mL bed volume. Transfer this spin-column to an appropriately sized centrifuge tube and spin at 100 X g (calculated for the radial distance to the tip of the column itself, and not the bottom of the centrifuge tube) for 2 min in a swinging bucket rotor". The volume of the now semi-dry gel bed will be reduced by 25-40%, and the media will appear as a gel mass that may even break away from the walls of the chromatography tube. (This is normal and will not affect performance.)... 

The tubes of the swinging bucket rotor type are accommodated in a pivoted bucket moving from vertical to horizontal position during acceleration under the influence of the centrifugal field. The sedimentation path length is lowest in vertical rotors and highest in swinging-bucket rotors. 

Operation of a swinging-bucket rotor. A Loading of sample. B Sample at start of centrifugation. C Sample during centrifugation separates into two components. D Rotor at rest. 

Tabletop centrifuge and appropriate swinging bucket rotor Vacuum filtering apparatus and Whatman filter no. 42 paper 30- to 50-ml tube with cap Shaking water bath or ultrasonic bath, 60°C...

Light scattering cells were of the type designed by Dandliker and Kraut (II) to permit the solution to be centrifuged in the cells for removal of dust. The cells were floated in sulfuric acid and centrifuged for 4—6 hours at 9000 r.p.m. in a Servall centrifuge equipped with a swinging bucket rotor. Cells suitable for use were selected from a hand-... 

The ground homogenate should be centrifuged at low speed (2500 rpm) for 5 min in a swinging-bucket rotor at 4°. The resulting pellet is discarded. Repetition of this low-speed spin (2500 rpm) 3 to 5 times ensures that most cellular contaminants and nuclei are pelleted and eliminated. Because the low-speed pellets contain nuclei, it is sometimes desirable to save these pellets for nuclear DNA preparations. 

Centrifuge with swinging bucket rotor and sealed microtiter plate carriers... 

The procedure can be further accelerated for the separation of components of very different densities using step gradients in a swinging-bucket rotor. Consider, for example, the separation of RNA and DNA. To separate these, the centrifuge tube is first half-filled with a CsCl2 solution of density 1.76 103 kg m-3, and this is overlaid with a less dense solution (ca. 1.65 103 kg m 3). Since DNA (ca. 

Figure 8-26. Adapter for the centrifugation of small capped plastic vials (Beckman Corp.). This adapter is for use with the Sorvall swinging bucket rotor or its equivalent. The centerpiece (A) extends to the bottom of the 50 ml tube well. Disk C is used as a means of centering the adapter in eonjunetion with the upper disk (B) of identical diameter. The test tubes are suspended by a lip from the upper disk. Centrifuging speed should not exceed 9000 rpm when this apparatus is used. Similar small plastic tubes (without caps) and four-place adapters are available commericially from the Sorvall Corp. These tubes may be centrifuged at significantly higher speeds without damage.

Figure 9-10. SW 40 swinging bucket rotor with the centrifuge tube holders or buckets in place. (Courtesy of Beckman Instruments, Palo Alto, Calif.)...

Following the manufacturer s instructions, centrifuge the tubes at 2°C for 5 hours at 23,000 rpm in a Beckman SW 25.2 swinging bucket rotor. Other rotors may be used but appropriate adjustments of speeds and time will be necessary (see preceding text). 

Figure 4.15. Zonal Centrifugation. The steps are as follows (A) form a density gradient, (B) layer the sample on top of the gradient, (C) place the tube in a swinging-bucket rotor and centrifuge it, and (D) collect the samples. [After D. Freifelder, Physical Biochemistry, 2d ed. (W. H. Freeman and Company, 1982), p. 397 ]...

When the rotor begins to accelerate, the density gradient adjusts to the new g forces that act upon it. In swinging-bucket rotors, the centrifuge tube follows the direction of the g force, and the gradient undergoes no redistribution. 

The cell suspension was placed in a 25 mL conical flask and centrifuged at l,500rpmor 238 x g at 4°C for 5 min in a swinging bucket rotor. The supernatant was withdrawn from the flask, and the cell pellet was washed with 5mL of PBS +. The cells were recentrifuged at l,500rpm at4°C for 5 min in a swinging bucket rotor. The PBS+ supernatant was withdrawn, and the cell pellet was resuspended in lmL of PBS+. 

---