TCA Precipitation

[Bill Melchior, NCTR/FDA]

>Does anyone know what is the lower limit of size for precipitable ds or ss
>nucleic acids by trichloroacetic acid? I am only familiar with precipitations
>on a glass fiber filter.  Is it possible to do precipitations in solution and
>then simply pellet the material by centrifugation?

The latest issue of BioTechniques (v12 #2, Feb '92) has a note on TCA 
precipitation, pp226-228, by KC Gupta.  He states that the smallest oligo
that can be measured reliably (my interpretation of his statement) by TCA 
pptn + filtration is ~50 ntides.  He spots the
solution on filter paper and then immerses the paper in TCA, getting
what appears to be pretty good results down to 10mers.

Bill Melchior                                ||   Evolution, as described in
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