Glossary
Fixed-angle rotor
A fixed-angle rotor holds tubes at a set inclination throughout the spin. It is compact and reaches higher speeds, but the layers separate against the tube wall on a slant, which makes a clean draw harder.
Figure
The slant
Figure. Fixed-angle rotors hold tubes at a set inclination, reported from 33 to 45 degrees across the literature. The buffy coat forms as a diagonal band against the tube wall, which is what makes a clean draw harder and less repeatable between staff.
In practice
Across the reviewed PRF literature, fixed-angle rotors ranged from 33 to 45 degrees. The angle is a property of the machine you buy and cannot be changed afterwards, which is why it belongs in the purchasing decision.
See also
- Swing-out rotorA swing-out rotor lets tubes rotate to horizontal under load, so the layers stratify flat and perpendicular to the tube.
- Radius-max (r-max)Radius-max is the distance from the centrifuge's axis of rotation to the bottom of the tube, usually given in millimetres.
- Buffy coatThe buffy coat is the thin layer that forms between the red cells and the plasma after centrifugation.