> the other question is, can i determine the protein content
> directly using dry samples (grinded leaves / roots) without
> doing the protein extraction as i only want an approximate
As far as I know, most protein determinations rely on absorbance in
solution. As a result, you're going to have to extract the protein,
because otherwise insoluble portions of the plant will float in solution
and interfere with the assay. Unless you have perfectly even
pulverization of the source material, the effect on your sample will be
unpredictable, and the results obtained will not even be approximate.
You could theoretically wait for that to all settle out, but since most
protein assays are also on a set time course there's no guarantee that
all the floaters will fall before you have to check the absorbance.
Just as a matter of curiosity, are you planning to look at the general
amount of protein in a given weight, or are you planning to look at the
amount of a specific but common protein?
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