Inquiry about DNA recovery by silica binding

colossus... s535290 at aix1.uottawa.ca
Mon Oct 20 22:40:59 EST 1997


> >  One more question is about the safety of guanidium thiocyanate...
> >  guanidium thiocyanate can release very toxic gas in acidic 
> >  solution. Is it possible that toxic gas released in the procedure
> >  (e.g solution III) of miniprep?
> 
> Though I was not aware of this little detail, I'll point out that solution
> three of alkalai lysis neutralizes an already basic solution (NaOH in the
> lysis buffer).  Since dna is susceptible to acid hydrolysis, you'd better
> not be ending up with an acid solution (I've not checked, myself).  I'd
> worry more about the large gamish of salts in that solution messing up the
> binding reaction, 

If the supernatant obtained after solution III addition is cleared enough
by centrifugation, the beads should do fine if added right then I am
currently using a kit that had been lying on one of our shelves a few
years which uses glassmilk exactly as you describe. All you do is clear
after neutralization and add glassmilk to the cleared supernatant. It
works beautifully,

Ed




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