If you are patient you can find cheap, used centrifuges in working condition, or nearly working condition. I bought a lot of 4 surplus centrifuges recently for $360, including a refrigerated Beckman Allegra R and 3 unrefrigerated Spinchron units. Both types have a 3-litre capacity, and can pull about 4,000g. They had been used in a VA hospital, then sat in storage for 6 years, which will bother some people. However, they can be disassembled and the parts autoclave sterilized (pressure canner) and chemically sterilized *very* thoroughly. It is a fair amount of work to do this, but it is not difficult. Also, I don't spin anything directly in the buckets anyway, I use brand new, sealed centrifuge bottles made to fit my rotor buckets. They were a little expensive at $130 for six bottles, but it's much more convenient. I reckon it's as safe as sterilized surgical equipment that is reused, as my sterilization process exceeded that used for surgical instruments and other reused medical equipment. Nobody is going to tell you to do this, including me, for obvious reasons. But I can tell you I haven't lost a wink of sleep over it -- I'm pretty confident nothing could survive my teardown + 10% bleach + autoclave cleaning of the equipment.
One of the 4 had been used as a parts donor; it's missing the motor and rotor. I'm keeping the refrigerated unit, and probably the parts unit and might consider selling the other two, but maybe not because everyone is squeamish about things and I am not accepting any liability.
Using it is fun as hell. I make clarified lime juice using the agar agar technique described on cookingissues.com, performing the speration in the centrifuge. Makes the best margaritas on the planet, and I haven't died from Ebola.
I just (today!) bought a Sorvall RC-5C for $42. That's not a typo. It is from a USDA lab that is being shut down, so no reason to believe it won't work. No idea what rotor it has yet, but this is the "washing machine" sized model they suggest in the MC books, capable of 51,000g, depending on the rotor installed. No need to screw around with agar agar to clarify lime juice, and it should squeeze out oil from crushed nuts. Or, it might be parted out, or not working, or have a rotor that only holds six 15ml test tubes. Oh well, it was $42. I can afford to buy a pig-in-a-poke for $42.
I know the bacteria thing is a big scare, and with good reason. But you have to remember these machines were made to do this work safely. Occasionally, test tubes break in a centrifuge and they need to be sterilized so they don't contaminate future samples. Hospital procedure involves sterilization after each use. The Sorvall manual has instructions for biological and radiological decontamination & sterilization because they need to be serviced and inspected occasionally, and this needs to be safely done. There are procedures to sterilize them, and they are effective.
That said, DON'T DO IT!!! You could kill yourself and everyone you know. You could start the next plague. You've been warned!
But I sure enjoy my margaritas!
Jim
PS: I also just bought two Rotavapor machines surplus for $146. Only one condenser, and it looks like they are missing the boiling/evaporating flasks, but I should be up and running for under $500. My rotor-stator homogenizer cost me $24. Don't know if it works yet. Just keep your eyes peeled, and be willing to do some fixing and cleaning. Or not. Probably better if you don't. :-)
