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G6PD - (Feb/26/2010 )

Hi all,

I bought a glucose-6-phosphate dehydrogenase type IX from Sigma aldrich (G4134) weight 0.6 mg solid. In my assay I only need a final amount of 1 unit of the enzyme. However, in the label, there are two different concentration unit. One is 192 unit/mg solid and the other one is 231 unit/mg protein. Which one should I choose? Should I choose 192 unit/mg solid since I know the total amount of the enzyme is 0.6 mg solid? What the purposed they put the value 231 unit/mg protein? Anybody knows?

Thank you



they are telling you that not all of the solid is protein. many like to know the protein concentration of the enzyme solution rather than the concentration of solids.

if you make your enzyme solution based on the amount of solid then you use the units/mg solid to determine how much to take for one unit.

if you make the solution based on protein content then use the units/mg protein to determine how much to use for one unit.