Protocol Online logo
Top : New Forum Archives (2009-): : Protein Expression and Purification

Problem with calculations for enzyme activity - (May/08/2014 )

I know it sounds trivial but i have some problems with calculations for the experiment that I've performed today in the lab. I was supposed to do the bioassay for the lysozyme, using 3 samples: crude, precipitation, dialysis and of course standards.


Preparation of satndards: 1mg lysozyme/ml of stock with/ spec activity of 47080 U/mg that needed to be diluted 20 times (I've used a total volume of 500ul, so 25ul in 475 ul of potassiumphosphate buffer)


Stand 1:

150 ul of potassiumphosphate buffer

150ul of diluted lysozyme stock


then what is enzyme activity in the standard solution (U/ml)?

I keep making some mistakes and i'm pretty sure of it


So your stock solution is at 1 mg/ml and therefore has 47080 U/ml and you want to know the concentration after dilution



47080 (U/ml) * 25 (ul) = 500 (ul) x C2


C2=??? U/ml


You can use the same equation to work out your stand 1.


thanks :)

i was using the concentration for it as 1mg/ml.. and then calculating it further to U/ml

I guess some calculations are usually way easier than I'm thinking