Do NTP's precipitate with ethanol? How efficiently?

Anton Scott Goustin asg at cmb.biosci.wayne.edu
Thu Feb 15 15:21:44 EST 1996


The information in Chi-Kuang's reply (above) is quite misleading.

Deoxyribonucleotide triphosphates are quite insoluble in mixtures of
EtOH and NaCl.  For example, if you precipitate a randon-primer reaction
by first raising the NaCl to 0.3 M and then adding 2.5 volumes of EtOH,
a substantial fraction of your dNTPs will come down with the DNA.  The
solubility of dNTPs, however, is substantially reduced in ammonium 
salts.  For example, a clean separation between dNTPs and DNA can be
achieved by first raising the concentration of ammonium chloride to 4
molar and then adding 2.5 vol EtOH.

Ppttn of dNTPs also depends on the base.  G is most insoluble, A is
most soluble.  The ribo versions of each NTP are also more soluble than
the deoxy versions.





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