Date: Wed, 8 Jan 1997 20:05:03 From: SCHLAUER@chemie.uni-wuerzburg.de To: cp@opus.hpl.hp.com Message-Id: <aabcdefg118$foo@default> Subject: Re: Nitrogen uptake
Dear nitrogen-Prof.,
> This was snipped from a missive from a prof at my alma mater; he
> suggests that labeled nitrogen is not viable (their NMR is only 80 Mhz),
> and that GC-MS would be a bear due to sample workup.
You should look for a group with sufficient NMR power as 15N
techniques are the state-of-the-art method to assay N takeup by
cps. Of course if only primary absorption is to be measured, 14C or
13C labelling of amino acids should work as well because usually
proteins are not digested beyond amino acids outside the plant. But
after the first transamination step (to be expected within the plant)
you will measure little but artifacts with labelled carbon.
For quantification purposes, make sure that no contamination of the
pitcher liquid takes place (use sterilized equipment and chemicals,
plug the pitcher mouth with e.g. sterile cotton as soon as the bud
opens) in order to prevent pre-oral parasitism (especially
transamination and denitrification!) by micro-organisms.
Kind regards
Jan
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