Dissolving Pepstatin A in DMSO - (Jan/11/2008 )

Hi all....

Iam here with a strange problem......
Brought a 1mg of Pepstatin A from Sigma and tried to dissolve the 1mg Pepstatin A in 1mL of DMSO.
In order to dissolve it I pipette it up and down close the bottle tightly and give a gud shake. Juz to check it has dissolved completely tried to take the solution in the pipette.......but there is no solution.....strange iam puzzled where did the 1mL of DMSO disappear all of a sudden . Since the quantity was only 1mg so there is no point in weighing out into another tube and trying to dissolve.So I had added the 1mL of DMSO into the bottle directly. Iam not knowing what to do? Anybody has faced any problem like this for making a protease inhibitor stock solution (Pepstatin A). now at the bottom of the bottle i see a precipitate and no DMSO. help me out what can i do.......

Thank you

The DMSO leaked out? Did you see anywhere wet and smell the DMSO smell?

check this info from sigma:

pepstatin spec sheet (sigma)