Ethanol precipitations: disposable 30 ml tubes?

[Harry J. Witchel]

Greetings Ferocious Mages of Nucleic Acids--
	
	I fear I have a contamination problem, so I would like to find a brand 
of disposable tube which can be spun quickly.  I fear that plasmids from 
my maxipreps of probe plasmids may get into my RNA preps.  I do all my larger 
ethanol precipitations (> 15 mls) in a small set of 30 ml corex tubes I have. 
 I would like to use a disposable tube for these ethanol precipitations, but I 
think that falcon blue tubes would fall to pieces at the speeds (12,000 rpm in 
an SS-34 rotor) which I find useful for precipitating small quantities of DNA 
(100 micrograms) out of 25 mls of solution.  Is there an appropriate tube/spin 
system for ethanol precipitations of larger volumes using disposable tubes.

	I don't think that washing up is a solution to the problem, because 
currently after using the corex tubes, I rinse them with water, soak them 
overnight with 10% (v/v) HCl to the brim, then I wash the tubes normally in 
soapy water etc. using a reserved set (ie post acid) of bottle brushes.  
Finally the tubes are baked at 180C for 7 hours.  

	Many thanks,
	Harry

Harry.Witchel at Bristol.AC.UK