Skim milk enhances the preservation of thawed -80 degrees C bacterial stocks.
The results from bacterial strain recovery efforts following hurricanes Katrina and Rita are reported. Over 90% of strains frozen in 10% skim milk were recovered whereas various recovery rates were observed for glycerol-stored stocks (56% and 94% of Escherichia coli, depending upon the laboratory). These observations led to a viability comparison of Streptococcus pyogenes, Campylobacter jejuni, Borrelia burgdorferi, Salmonella enterica subsp. Typhimurium, Pseudomonas aeruginosa and E. coli strains stored in glycerol or skim milk. In all bacteria examined, 10% skim milk resulted in significantly longer viability after thawing than 15% glycerol solutions currently used in most laboratories.
Department of Microbiology, University of Colorado Denver, School of Medicine, Aurora, CO 80045, USA.
William L
WL
Cody
James W
JW
Wilson
David R
DR
Hendrixson
Kevin S
KS
McIver
Kayla E
KE
Hagman
C M
CM
Ott
Cheryl A
CA
Nickerson
Michael J
MJ
Schurr
D000818:Animals; D001419:Bacteria / Q000166:cytology / Q000254:growth & development*; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D005990:Glycerol / Q000494:pharmacology; D050296:Microbial Viability / Q000187:drug effects; D008892:Milk
D003451:Cryoprotective Agents; D005990:Glycerol