Glycerol in Freezing media

[dna]

In article <3248D5D3.4F9A at sprynet.com>, bbbbd at sprynet.com says...
>
>Hi.
>        I was wondering exactly it is necessary to have glycerol in 
freezing
>medium for bacteria, yeast, and animal cells.

 Yes it is.
Try a little experiment where you add no glyc. 10%, 20%, 30% ...
Freeze them at - 80C overnight.
Then plate 50ul on non-selective media.
This will show you the results.

The Glycerol supposedly keeps ice crystals to a minnimum which allows the 
cells to survive.

-- 
John R. McQuiston
Molecular Genetics Lab
CMMID VMRCVM
VPI & SU
1410 Prices Fork Rd
Blacksburg VA 24061
jmcquist at vt.edu