protein purification - preserve pellet (Feb/02/2006 )
Hi everybody,
I am doing a protein purification and I would like to conserve my pellet after the centrifugation of the inducted BL21 cells to continue the protocol a few days later. But for this, should I just take off the supernatent and freeze the pellet at -20°C? 
-vik-
QUOTE (vik @ Feb 2 2006, 02:33 PM)
Hi everybody,
I am doing a protein purification and I would like to conserve my pellet after the centrifugation of the inducted BL21 cells to continue the protocol a few days later. But for this, should I just take off the supernatent and freeze the pellet at -20°C?
I am doing a protein purification and I would like to conserve my pellet after the centrifugation of the inducted BL21 cells to continue the protocol a few days later. But for this, should I just take off the supernatent and freeze the pellet at -20°C?
YES!
We do this with our pellets after expression. These pellets stored without the supernatent in the -20C freezer for very long time, weeks or month. We defrost these pellets on ice and continue with the original protocol.
But: We know from tests that the fresh used pellets (the proteins) are more, lets say, active! With frosting we have a lot of protein fragments, degradation and inactive proteins. Therefore the yield with fresh pellets is muche higher.
Oli
-ms-olli-
QUOTE (ms-olli @ Feb 2 2006, 02:45 PM)
QUOTE (vik @ Feb 2 2006, 02:33 PM)
Hi everybody,
I am doing a protein purification and I would like to conserve my pellet after the centrifugation of the inducted BL21 cells to continue the protocol a few days later. But for this, should I just take off the supernatent and freeze the pellet at -20°C?
YES!
We do this with our pellets after expression. These pellets stored without the supernatent in the -20C freezer for very long time, weeks or month. We defrost these pellets on ice and continue with the original protocol.
But: We know from tests that the fresh used pellets (the proteins) are more, lets say, active! With frosting we have a lot of protein fragments, degradation and inactive proteins. Therefore the yield with fresh pellets is muche higher.
Oli
Thanks a lot for your reply!
Vik
-vik-