TCA on nucleic acid

Drew Smith drsmith at shaman.nexagen.com
Fri Jun 24 13:55:52 EST 1994


eqfvari at dingo.cc.uq.oz.au (Frank Vari) writes:

>Could anyone please tell me what the effect of 10% aqueous trichloroacetic
>acid (TCA) is on nucleic acids? Are there any good references that someone
>could point me in the direction of? Please Email me or post a response here. 
>* Frank Vari at the Australian Equine Blood Typing Research Lab.    *
>* University of Queensland, St Lucia, Brisbane, Australia, 4072.    *
>*	Email:	F.Vari at mailbox.uq.oz.au                             * 


At low pH, the phosphate backbone of the DNA is protonated, causing it to
become uncharged, and thus insoluble in water - this is why it precipitates.
The N7's of guanosines are also protonated at pH<2 - this causes depurination,
followed by strand cleavage.  Although this reaction is not terribly fast,
it damages the DNA enough that TCA ppt'n is not suitable as a preparative
method - it can be used for analytical purposes, such as filter binding
assays.

Drew Smith
drsmith at nexagen.com





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