Hi all, I have a big doubt about a step on this protocol.
We talk about a protein lyophilized, hygroscopic.
1) set balance to zero
2)Remove cap from vial
3)Weigh the protein into weighing device
4) Close vial
5) Reord mass of the Protein in the weighing device
6) Transfer Protein into a sample dilution vassel
7)Weigh back weighing device on the balance, record mass and calculate mass of Protein transferred to the sample dilution vessel
8)dissolve protein in sample dilution vessel in an apropriate amount of 60% (v/v) ethanol
9) Calculate protein concetration on the basis of the protein content of dry substance.
10) close vial and store the protein.
I have doubts about the step 7. What do they mean with "calculate mass" ? could be something connceted with the poit that this protein is hygroscopic? How can I do this step?
thank you in advance for any reply.