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Question on culture expiration - (Jul/11/2008 )

I need two strains of archea for research. I intend on ordering them from DSMZ, but I need to know if the dry (vacuum) cultures they send expire relatively quickly.

If I order the strains I need, will I have a week, a month, or a year before the culture is no longer viable. I believe you just have to rehydrate the pellet they send you according to their specified medium, but how long will the pellet last before rehydrating won't rejuvenate the culture?



Think DSMZ could tell you.


QUOTE (jorge1907 @ Jul 11 2008, 01:06 PM)
Think DSMZ could tell you.

I'm not sure how the dry culture affects the organism. I just need the strain to extract genomic DNA, which I have a kit for here at the lab. Would the strain need to be rehydrate to extract DNA, or do I just need to lyse the pellet?


I recently ordered 4 different strains from DSMZ as dried cultures for "pinching" some genes. I simply resuspended the cultures in the recommended medium added equal volume of 30% glycerol and stored in the minus 80 in aliquots. The dried cultures they send contain quite a lot of cell mass (equivalent to say 10 or 20 ml saturated e.coli culture pellet), as for how long the pellet will last I assume they are viable for years, no water no chemistry, I am pretty sure some of mine were made last year at some point. I also grew my cells out of curiosity on agar plates and in liquid cultures. The plates were OK except for the moderate thermophile strain I had which grew better in liquid media at 60C, although it took a week. I also found that doing colony PCR was as good as genomic DNA isolation for amplifying out the genes I wanted. I would also check the literature for simpler media recipes as some of the ones DSMZ recommend are extremley tedious and you may find a reference where they simply grow it in LB or something similar! I found this with one of my strains (Rhodopseudomonas palustris), after I had made the complex media of course dry.gif


Lysing the pelllet meaning directly processing the dehydrated material sent by DMSZ? Probably not a good idea as you'll not be able to describe how the culture was prepared (for eventual publication) and you would want to conduct some level of testing to confirm you received from DSMZ the culture you requested.