Storing tissue for protein and RNA extraction? - (Feb/19/2008 )
HI,
I have a bit of problem getting good results for my Western blot...i.e. sometimes I get a good band for the protein of interest, other times, following the same steps etc, I get poor signal. I store my tissue sample post snap freezing at -80 Degree C and was wondering if that is sufficient. Another person in the department said he stores his samples in Liquid nitrogen for tissue intended for RNA and protein extraction.
I was wondering if anyone can comment on what storage condition to use to achieve good quality RNA and protein samples. We do not have liquid nitrogen facility in my lab.
Many thanks.
Sindy 
I store plant material at -80ºc and it's fine for a long time (we don't have liquid nitrogen storing facilities too).
Hi Ambrósio
Thanks... that is good to hear! Just wondering if there is a different in storing mamalian versus plant tissues...
Can't help you there - I only work with plants...
Nope, no for me though. I store my protein extracts at -20 and they are still good after.. let's say several months. Maybe you problem resides more in the freeze/thaw than in the protease contamination..
Hi Madrius
I don't freeze thaw samples... they are stored in small aliquotes and once thawed, they are used and remaining samples discarded...
Any other comments/suggestions...
Sindy
Hi skll, even i face the same problem. Even though i dont freeze thaw the sample and store at-80 c, it gets denatured.
-80'C. best option.
V
V
Thanks V and vinuuuu..
It seemed that most people would store their tissue and protein samples at -80DegC. Anyway, what about RNA samples?
vinuuuu: how do you overcome your protein degradation problem... I suppose if you store at -20DegC... it is a non- frost free freezer... as frost-free freezers tend to cycle their temperature, sometimes to about -10DegC... and hence can cause freeze thawing effect at times...
Cheers
Sindy
RNA is stored at -80'C.
protein degredation can be stopped by using protease inhibitors... usually in a cocktail. tablets can be disolved in water, and then added to the lysis buffer you're using.
V