1% acetic acid, insulin will not dissolve in water or any neutral pH buffers. The solvent has to be acidic, to make stock. 

Thank you. I will be performing an experiment in which I am attempting elution of the insulin from the MOF (CD-MOF), and I will use an acidic solution to do so. For the initial stage of my experiment, in which I am incubating the insulin with the water-sensitive CD-MOF, I will first try dissolving insulin in a 90% DMF solution, based on this article I have found here:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1302733/

Hopefully the 10% water will prevent denaturing of insulin, and the 90% DMF will prevent denaturation of CD-MOF.

Dear Elise,

At neutral pH insulin will take longer to dissolve. The electric point (pI) of the insulin molecule is 5,8.

You should take care with the following:

1- The insulin solution should not be held at pH 3 for more than one hour.

2- Readjust pH to 7.4 with buffer . The solution becomes unclear when passing through the isoelectric point of the insulin product, but becomes clear again as the pH of the solution reaches 7.

3- The solution should be sterile filtered using a low protein binding filter with a pore size of 0.2 µm. Aeration and foaming should be avoided during solubilization and filtration, as this can lead to protein denaturation.

Elsie Wilson Hi, did the 10% water and 90%DMF solvent work for you? did you use any other solvent system? Any information on this would be helpful.

Thank you.