Sterilization - Sterilization of herbal extract (Nov/17/2009 )

Hi
I have been assigned a task to extract a ethanolic fraction from various herbs. I have to freeze dry it and then dissolve the residue in water along with DMSO of PVP (to increasse the solubility of non-polar constituents). I have to use this in cell culture experiment.

My question is
How can i sterilize this herbal preperation........autoclaving wont be suitable as it degrade heat labile constituents and I am not sure about filtration of emulsions.

can you filter sterilize??!!! wait for more opinions!!

might help!!!

thanks for the paper
its informative
but my extract would be in emulsion form and it is difficult to sterilize by filtration
i m thinking of sterilizing it by sonication (water bath)
any suggestion on that

z0z

well that can be fine but check if your protein will still be active in those conditions!!!

z0z on Nov 18 2009, 06:59 PM said:

I wouldn’t rely on sonication for sterilisation, even the high intensity sonication probes are unlikely to be completely effective.

How clean is your freeze drier? The solvent extraction tends to do a good job of sterilizing plant material. As long as you can get samples on and off the freeze drier without introducing contaminants (I use cotton wool in the top of the vessel to help) you should be fine. Once or twice we’ve put samples through an autoclave to make doubly sure of sterilisation but this always makes me nervous about losing activity.
If you want to confirm that you have got it right, or want to check out a number of options, a micro test isn’t that expensive c.a.$100.

Good luck.