Amount of DMSO to dissolve peptide - please help me to check if my calculation is correct!! (Jul/16/2009 )

it can be a problem but you can avoid it.

what i do:

with a manual pipette, set to a little less than the volume (easy to figure, you know how much solvent you put in) slowly (to accommodate wall (of the tube) effects) then slowly increase the volume of the pipette while immersed in the solution until it is all picked up. then read the volume.

with a electronic pipette, set the pipette to its slowest. pick up solution, occasionally stopping to accommodate wall effects.

in either case, expel the solution back into the tube slowly to ensure complete transfer.

wow.. thanks a lot. i really learned some new stuffs from you people.

I am unable to increase the volume of the peptide because it comes in a powder form and it came in this bottle where the total mass is 9.2mg and I am supposed to dissolve all the powder before I can use it for my work..

jiajia1987 on Jul 20 2009, 03:26 AM said:

I really wonder you can dissolve this amount in such low volume of DMSO.
Let us please know if it worked out or not.
I am really curious.

Yes it works, I did it and it really dissolved.

Now I have this other peptide which is 6.2mg and has a molecular weight of 1834.98g/mol and I will be adding 337.9uL DMSO to make a 10mM stock.

jiajia1987 on Jul 21 2009, 03:17 AM said:

Yeah, you need to add DMSO untill you reach 337.9µl in total. (not adding 337.9µl DMSO till you reach 337.9µl + X l; total volume needs to be 337.9 as mdfenko allready explained.)