RNA preps - looking for suggestions

Hiranya Roychowdhury hroychow at NMSU.EDU
Mon Jun 8 16:27:11 EST 1998

At 09:48 AM 6/6/98 -0400, Matthew L. Beyers wrote:
>Hello all,
>I'm currently doing GITC/Phenol/Chloroform RNA preps using Corex #8445
>30 ml tubes and doing my spins at 10,000 RPM in a Sorvall SA-600 rotor.
>I'm having a bit of a problem though in that sometimes the tubes shatter
>during the spin, meaning that I lose all of my sample.  I've called
>Fisher and they've said that the people that make Corex (Corning?) have
>discontinued that tube and that there is no replacement available.
>I was hoping that someone out there would have an idea for a substitute
>for these tubes that is reasonably easy to see through (like the glass
>of Corex) able to withstand phenol and chloroform and the high (~16,000
>RCF) g forces necessary.  Any ideas?
>Thanks a bunch,

I used to use Corex tubes when I was a grad student. There used to be two
kinds of those available, one with thick walls (10mL working capacity) and
the other with thin walls (12 mL...). The thick-walled type did shatter at
speeds above 10,000 rpm in Sorval SW28 rotors. The other kind could be spun
at 15,000 rpm without problem. I had even tried short (5 min) spins at 18k
rpm with those and never had a problem.
However, we, in this lab use polypropylene Oakridge tubes from Nalgene for
NA purifications. These are resistant to most solvents but does bubble out
if kept with CHCl3 for extended periods of time (eg overnight). They are
autoclavable and can be baked overnight (~8-10 hrs) at 80 C. However, unlike
Corex tubes, they do have a much shorter life following repeated
autoclavings and uses with PCI CI etc. They also lose their translucence
after about 3 or four uses. 
Hope this helps.

Dr. Hiranya Sankar Roychowdhury
Plant Genetic Engineering Lab.
New Mexico State University
Las Cruces, NM 88003
Ph. (505) 646-5785
hroychow at nmsu.edu

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