Centrifuges

The centrifuge is a commonly used tool in laboratory research. It uses centrifugal force to separate substances in liquid or solid media according to particle size and density differences. Centrifugation may present two serious hazards: mechanical failure and dispersion of aerosols. Therefore, training on how to use the centrifuge properly and safely is essential for all new employees as part of Lab-Specific Training.

Safe Procedures for Centrifugation

Before centrifugation

  • Train each operator on proper operating procedures, review the user manual. 
  • Use only rotors compatible with the centrifuge. Check the expiration date for ultracentrifuge rotors.
  • Check tubes, bottles, and rotors for cracks and deformities before each use.
  • Make sure that the rotor, tubes, and spindle are dry and clean. 
  • Examine O-rings and replace if worn, cracked, or missing. 
  • Never overfill centrifuge tubes (don't exceed ¾ full). 
  • Always cap tubes before centrifugation. 
  • Always balance buckets, tubes, and rotors properly.
  • Check that the rotor is seated on the drive correctly, close the lid on the centrifuge, and secure it.
  • When using swinging bucket rotors, make sure that all buckets are hooked correctly and move freely.

 During centrifugation

  • Keep the lid closed at all times during operation. Never open a centrifuge until the rotor has stopped. 
  • Do not exceed safe rotor speed.
  • The operator should not leave the centrifuge until full operating speed is attained and the machine appears to be running safely without vibration. 
  • Stop the centrifuge immediately if an unusual condition (noise or vibration) begins and check load balances.

After centrifugation

  • Allow the centrifuge to come to a complete stop before opening. 
  • Wear gloves to remove rotor and samples. 
  • Check inside of centrifuge for possible spills and leaks, clean centrifuge and rotor thoroughly if necessary. 
  • Wash hands after removing gloves.

Centrifuging Infectious Materials or Human Samples

Follow the safety procedures above, plus:

  • Place a biohazard label on the centrifuge.
  • Always wear gloves when handling tubes or rotors.
  • Avoid the use of celluloid tubes with biohazards. If celluloid tubes must be used, an appropriate disinfectant must be used to decontaminate them.
  • Always use sealed safety cups, safety buckets, or sealed rotors with )-ring as secondary containment if available.
  • Fill centrifuge tubes, load into rotors, remove from rotors, and open tubes within a biological safety cabinet if biological safety cabinet is available.
  • Wipe exterior of tubes or bottles with disinfectant prior to loading into rotor or bucket. Seal rotor or bucket, remove outer gloves, and transport to the centrifuge.
  • Always wait at least 10 minutes after the run to allow aerosols to settle before opening the centrifuge. Check for possible spills or leaks. For spills of infectious materials, see Centrifuge Emergency Procedures.
  • Decontaminate centrifuge interior, safety cups or buckets, and rotors if tube breakage occurs. See Centrifuge Emergency Procedures.
  • Include centrifugation procedure and decontamination plan in lab SOPs.