One of my compound has been dissolved in DMSO for the enzyme inhibitory assay as stock solution. Now I need to recover it from DMSO. Is there any quick method to recover it? The compound is a sterol.
You can probably try HPLC; or if the MW of your compound is much different from DMSO, try ultrafiltration. Alternatively, low percentage of DMSO in final assay may not affect the reaction. Normally stock solution needs to be diluted anyway.
You could also try to extract the sterol from DMSO using ethyl ether or heptane. Those solvents should not be miscible with DMSO and are easy to evaporate.
Just speed-vac the DMSO away. Shouldn't take more than an hour.
I would suggest dialysis, several times in a large volume of solution.
If you only have a few milligrams of your sterol dissolved in a small volume of DMSO then you can try any of these two quick methods:
Method 1: Using a regular 6-inch Disposable Glass Pasteur Pipettes with a small cotton plug in the narrow end and about 1-inch or so of silica on top. You could use this set up to simply retain your sterol and elute the DMSO. Following standard chromatography, you could then elute your pure sterol.
Method 2: Using an appropriate Sep-Pak Cartridge, a syringe and collection vials, you could achieve the same result in like manner.
Both methods would take about 5-6 minutes and give excellent recovery and purity.
If you have say, gram quantities of your sterol in DMSO (which I doubt would be the case for an enzyme assay) then HPLC; MPLC; flash chromatography; solvent extraction or ultracentrifugation would be good alternatives.
Good luck.
I agree with Timothy. Lyophilization or a 'Speed-vac' should be the fastest, cheapest and least destructive technique. We do that all the time in the lab.
What is the purpose of yours to get it back.....I think that should be the major concern.
All the methods written above are really appreciable but as a biochemist we used to use DMSO very often to dissolve our compounds and in-many cases we are afraid of using the DMSO dissolved compound as we have a concern regarding how that affect our enzyme (For biochemical, kinetic and crystallization purpose).
So, what we used to do is to prepare a relatively high concentration of the small molecule while dissolving in DMSO and then dilute it according to our requirements for the experiments with the buffers required for that very experiment.
I know this is not a direct answer of your question but sometime it helps.
Best of luck.
Thanks all. I need to recover my compound for further bioassays........... the amount used up is 12-14 mg. As an organic chemist, I often deal with the dissolution/recovery processes with more volatile org solvents. Now as it is DMSO, the same techniques are not working at all. I will try the speed vacuum but i think before that i must add hexane/ether to the solution as as to more speed up the process. I doubt simple micro column may work. But will have a deeper look....
As we talk, I am using a speed vac to remove DMSO from an organic compound stock. Because I have only 100 microlitres, it takes a couple of hours to get done. If you have a larger volume, I would suggest making aliquots of 200-400 microlitres and let the speedvac run overnight if possible.
Often it happens to me to perform nmr measurements in dmso. To recover the sample, add about a same volume of water, place the solution in a large container (i.e. A crystallizer), then I freeze the sample and put it into a lyophylizer. You should obtain a fine powder of your compound
- Badges
- Science topic