3 replies to this topic

[chicken]

i have  some lb broth for about 4 to 5 days old in fridge 4 c.

can i make there glycerol stock and also can i use them for growing new cultures.

confusion. how long  a cultre can be placed in fridge 4c without glycerol.

[tsng]

I've kept cells for a month without glycerol, but obviously not advisable as most cells die once it runs out of nutrients.

You can use your glycerol stock to make a new stock. All you really need is to scrape some off your glycerol cell stock with a heated loop or pipette tip and put into LB media.

[leelee]

Take some of your refrigerated culture and culture for several hours, then make your glycerol stock from that.
It was my understanding that glycerol is added to a culture prior to freezing to help prevent ice crystal formation, therefore there is no need to have glycerol added to refrigerated stocks, however I do agree with tsng that long term storage of bacteria at 4C is unadvisable.

[HomeBrew]

chicken, on Jul 15 2009, 12:36 AM, said:

i have  some lb broth for about 4 to 5 days old in fridge 4 c.

can i make there glycerol stock and also can i use them for growing new cultures.

confusion. how long  a cultre can be placed in fridge 4c without glycerol.

I agree with the others.  There is no need for glycerol when storing at 4C -- glycerol is a cryoprotectant, and therefore is useful when freezing cultures, not when refrigerating them.

A good number of your cells at 4C will likely still be alive.  Just swap the order of your intentions -- use the 4C cultures to start new ones, and make glycerol stocks from these new cultures.

As for how long a culture can retain viable cells at 4C, it depends greatly on the strain of bacteria, the media they're in, the density of the culture when stored, etc.  But such a culture should retain some viability for a few days at least, several weeks at best.