humic acids anyone?
Honorio Americo Campos
hcampos at SHADDAM.USB.VE
Thu Sep 8 23:03:38 EST 1994
Jean-Pierre Herveg,Louvain, <Herveg at bian.ucl.ac.be> says
%Humic acids! I learn the existence of these compounds from Hagelberg
%Humic acids contaminate some archaeological bones ... , they are
%together with the DNA! So when regions of mtDNA are submitted to PCR
%amplification for haplotype determination, they inhibit the DNA Pol!
%How can we purify this DNA to avoid this kind of contamination, easy
%recognize because the DNA solution is colored in brown!
%The purification technology requires some knowledge about those
%What are they, what property can be used to separate them from DNA?
%Another question, What are the monomers of humic acids?
"Humic substances are probably the most widely distributed natural
the earths surface...". "Organic matter of soils and waters consists
mixture of plant and animal products in various stages of
matter is usually divided in two groups 1) non humic substances 2)
substances. Non humic are compounds that exhibit still recognizable
characteristics (carbohydrates, proteins, fats, waxes, etc, etc). The
the organic matter consists on humic substances, they are amorphous,
black, hydrophillic, acidic, polydisperse substances of molecular
ranking from several hundreds to tens of thousands". They are further
classified, according to their solubility in acid and alkali, in a)
b)fulvic acids c)humin.
All humic fractions are resistant to microbial degradation and able to
stable water-soluble and water-insoluble salts and complexes with
metal ions and
hydrous oxides and to interact with clay minerals and organic
My only reference about the topic (listed below) talks about 4
their origin, nevertheless I believe it has been proved that they come
incomplete degradation of lignin and complex polyfenolic substances. I
appreciate if somebody has more updated news on the subject (my
I am just geting into this, but there is a good basic book, rather old
basic, good chemistry does not change, just keeps geting better !!!)
HUMIC SUBSTANCES IN THE ENVIRONMENT
by M.SCHNITZER AND S.U. KHAN
MARCEL DEKKER, INC, NY 1972
lots of chemistry there, could probably give a key on how to sort DNA
wonder why they mix, too... both are negatively charged, perhaps both
positively charged clay particles in the soil and geting there
cannot isolate one from the other)(pure especulations, so please dont
be hard on
Thanks a lot for the input received and for the references !!!
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