Hello All,

We have one of those unfortunate situations that sometimes arises from 
temporary technician inconsistency and hindsight. After finishing a number of 
analyses for macronutrients in some plant samples, we have discovered that some 
of the samples were properly frozen at -80 before lyophilizing, while others 
were simply blotted dry and placed in the freeze drier immediately after 
blotting.

I am concerned about the effects of these differences in our interpretation of 
protein, carbs, lipids, phenolics and elemental profiles. Does anyone have any 
unpublished data that can shed any light on this (certainly there is nothing 
published because it is a failure in normal protocol)? I imagine things like 
CHN analyses will not be affected, but what about phenolics or macromolecules? 
Does anyone know how long it will take for a wet sample to actually freeze in a 
freeze-drier before the water begins sublimating? I would do the test myself, 
but unfortunately our labs got trashed by the two category 5 hurricanes we had 
and we don't have an operating freeze-drier at present.

Any suggestions will be welcome,

Thanks,


Edwin

=================
Dr. Edwin Cruz-Rivera
Associate Professor
Department of Biological Sciences
University of the Virgin Islands
#2 John Brewers Bay
St. Thomas 00802
USVI
Tel: 1-340-693-1235
Fax: 1-340-693-1385

"It is not the same to hear the devil as to see him coming your way"
(Puerto Rican proverb)

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