Posted 26 September 2003 - 01:22 AM
I have been trying to concentrate protein. Our lyophilizer showed the proper temp and vaccum settings but still my sample thawed. Any idea why? What other option do I have, as I want viable protein and my sample is in litres?
Thanks in advance
Posted 01 October 2003 - 06:40 AM
If your protein is big enough I could recommend you the method used in our lab.
I use Amicon Ultrafiltration Stirred Cells for concentrating a 24kDa protein routinely.
The largest cell, to my knowledge, holds up to 400ml solution.
I'm concentrating up to 2L of protein solution successively in 5 turns, and it works fine for me.
I use filters with 3,500Da molecular weigth cutoff (MWCO), so nothing is lost. If your protein is smaller, you will have to try it yourself once. The manufacturer says it's safe for proteins larger than 2 times the theroretical MWCO of the filter mebrane, but that could be a bit close. In my case the 24kDa protein is filtered through a 10kDa MWCO membrane. The concentrated protein is native and functional in all assays.
And you can diafiltrate your protein at high speeds with much less buffer waste after concentration...
Posted 06 April 2004 - 06:31 AM
Posted 06 April 2004 - 08:35 AM
I hope, you can cope with your problem
Posted 08 April 2004 - 01:15 PM