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enzyme extraction : linamarase - questions about the cassava leaf enzyme extraction experiment. (Oct/10/2007 )

firstly, i would like to know how to prepare 100 ml of 100 mM Na citrate at pH 6 containing 10 g litre-1 polyvinylpolypyrrolidone, (Molecular weight of Na citrate = 294.1; molecular weight of polyvinylpolypyrrolidone = 40,000).

and why is it that water is used in the elution of the phenyl-sepharose column?

the link is here, a little long though,%20258-262.pdf

and from table one, how do we calculate the purity?

thank you all soooo much.


i'm not sure i should answer this rather than guide you to the answer, but, here goes....

first, i answered the elution question under "homework".

fold purity is determined by dividing the current step's specific activity by that of the starting material or the previous step. actual purity is determined by specific activity.

to prepare the buffer, you know the formula weight of the buffer. that is the number of grams you need for 1 mole. a 1 molar solution is 1 mole in a final volume of 1 liter.

when preparing a buffer, you suspend the chemical to less than final volume, adjust the pH then bring to final volume.

you don't need to know the formula weight of the pvp, you are making a percent solution of it. just add the amount of pvp you need to obtain the concentration (percentage) that you need for the volume that you are preparing (hint: add the pvp prior to adjusting to final volume).

hope this helps.