after expressing the protein can I store it for some days in -20 before purifica - (Feb/07/2006 )
I am expressing my protein in BL21 strain of Ecoli....so after I induce it with IPTG and centrifuge to collect the pellet...can I just store this pellet at -20 for 2-3 days? or it is better to proceed directly to purification? thanx for the advice.
hi
you can stably store a bacteria pellet for 2-3 days.
I assume it's better to do directly the purif, but freezing bacterias do not show lose of quality of the recovered proteins.
I agree with Fred
Hello
If you're going to lyse the pellet anyway it's sometimes better to resuspend the pellet then freeze it. I alwys seem to get a better yield because the cells lyse easier. I've stored the pellets like this for a month before and haven't suffered any loss of protein.
Rachel
If you're going to lyse the pellet anyway it's sometimes better to resuspend the pellet then freeze it. I alwys seem to get a better yield because the cells lyse easier. I've stored the pellets like this for a month before and haven't suffered any loss of protein.
Rachel
thanx a lot everyone....i will resuspend the pellet in PBS and then treat it with lysozyme....so i just centrifuge, remove supernatant and resuspend in PBS and freeze and after like 2-3 days treat it with lisozyme....is this what you meant? thanx
It should be OK.
Alternative, you may just pellet the bacteria and discard the medium, then freeze it at -80C prior to purificaiton. Of course, you may also resuspend the pellet in lysis buffer then freeze it at -80.
Hello khaty :):)
i worksince 5 years on protein expression in procaryotic system, if your protein expression is intracelluar, you can leave the cell pellet up to 2 months at - 80°C , " weeks if storage is at -20°C, i have try with the two conditions and i never loss any activity or any effect on protein yield, so don't worry !
Imen ;)
thanx everyone... 