16 July 1997
In response to my asking about the routines people use for
freezing with the agar method, we received 8 replies.
One person had no good experience with the agar method
at either -80C or LN2 and has switched back to the
glycerol method.
Here are the results of the 7 people who do use the agar
method:
A. All 7 people use agar method at -80C for their working
stocks and use LN2 only for backups.
B. Regarding titers of live worms after taking repeated
aliquots from -80C agar stocks:
2 had no obvious problems
2 saw a decrease in the titer in the later aliquots.
3 had no comment about this
C. Regarding the LN2 samples:
5 use agar method for these too, but have not tried
multiple aliquots from them.
1 uses glycerol for LN2
1 had no comment about this.
We have decided to go back to the glycerol method as we are
very limited for space at -80C. We believe that because the
LN2 samples are so hard, getting multiple aliquots from them
probably requires too much harmful thawing and freezing of
the remainder.
Our thanks to everyone who responded.
Raja Rosenbluth, in Baillie (BC) Lab
