avatar: asgor
1 posts
Replied to asgor's post on September 26th, 2012

What problem emblance of centrifuge?


avatar: Glenn PICKETT
72 posts
Replied to asgor's post on September 27th, 2012

Hi Asgor,

A few things to consider:

- Samples must be equally distributed in number & weight across (a) the drive axis, and [for swing-out rotors], (b) across the bucket swing axis. Samples should be balanced to about ±1g (levelling by eye is usually good enough).

- In a swing-out rotor, a little grease should be placed under the buckets where they swing on the rotor pins. This grease should be replaced monthly (removing the old grease first, or dust & grit can be there and imbalance can still occur. With no grease or dirty grease, buckets will swing out at different rates, creating major imbalance. Food grade molybdenum grease is best.

- Make sure that no broken material is left in the bottoms of pockets (in angle rotors) or adapters or buckets in swing-out rotors, after a tube breakage.

- Check that there is no water in the buckets from condensation (happens occasionally in refrigerated centrifuges, and not always equally distributed).

Remember: 3 mL of water (3 g at normal 'g') weighs 6 kg / 13.2 lb at 2,000 x g and 60 kg / 132 lb at 20,000 x g so take care with rotor loading and balancing.

I hope this helps. If you're interested, I can negotiate an interactive training course in centrifugation for your lab/establishment.