Blood Component Separations; General Operating Information; Rotor Balance; Bucket Rotors - Beckman Coulter Avanti J Series Instructions For Use Manual

Rotors

General Operating Information

Blood Component Separations

Centrifugation is the primary method for processing blood because it provides the required high
throughput, reproducibility, and versatility. Most blood components can be separated in one or
two runs. Generally, two types of runs are performed.
• Soft spin runs, short centrifugation runs (3 to 5 minutes) at low g-forces (2000 to 3000 × g) at
ambient temperature, are used to keep small cells or platelets in suspension while the larger
cells sediment. This type of run is used to obtain platelet-rich plasma and red blood cell
concentrate from whole blood.
• Hard spin runs are longer (5 to 7 minutes), at higher g-forces (4000 to 5000 × g), at ambient
temperatures or at 4°C, and are used to separate fresh plasma from cellular components.
Soft spin and hard spin techniques are often combined. Refer to
information about separation of blood components by centrifugation.
General Operating Information
Careful centrifugation technique is essential, because forces generated in high-speed centrifugation
can be enormous. For example, 10 grams at the bottom of a JA-25.50 fixed-angle rotor rotating at
25,000 rpm exerts the gravitational equivalent of 0.8 ton of centrifugal mass at the bottom of the
tube cavity.
NOTE
Specific information about filling, sealing, and capping containers, loading rotors, etc., is contained in
later sections.

Rotor Balance

If sample quantity is limited and the rotor is not balanced, do one of the following to balance the
rotor, depending on the rotor in use:
• Load the opposite rotor cavities or buckets with tubes containing a liquid of the same density as
opposing tubes.
• Layer a low-density, immiscible liquid, such as mineral oil, on top of the sample to fill opposing
tubes to the same level.
1-16
The mass of a properly loaded rotor is evenly distributed on the centrifuge
drive hub, causing the rotor to turn smoothly with the drive. An improperly
loaded rotor will be unbalanced; consistent running of unbalanced rotors will
reduce centrifuge drive life. To balance the rotor load, fill all opposing
containers to the same level with liquid of the same density. Weight of
opposing containers must be distributed equally. Place tubes in a fixed-angle,
vertical- tube, or JS-24 series swinging-bucket rotor symmetrically, as
illustrated in Figure 1.6. Detailed information about balancing other swinging-
bucket rotors is contained in
APPENDIX D
CHAPTER 5.
for further
PN JR-IM-10AG