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The preservation of micro‐organisms in biological specimens stored at – 70°C
Author(s) -
Ludlam H.A.,
Nwachukwu B.,
Noble W.C.,
Swan A.V.,
Phillips I.
Publication year - 1989
Publication title -
journal of applied bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 0021-8847
DOI - 10.1111/j.1365-2672.1989.tb02512.x
Subject(s) - biology
The preservation of micro‐organisms that may be found on the skin was studied by storage in liquid media at ‐70°C. In the first part of the study the performance of 12 varieties of suspending media was evaluated with pure cultures of 17 species of micro‐organisms maintained in the laboratory. After storage for 1 year the best medium (Oxoid Nutrient Broth with 15% glycerol) showed a mean survival for all organisms studied of 83.8%, with no significant differences between organisms. Even the worst medium (distilled water) permitted greater than 40% survival at 1 year. No changes in the characteristics of these micro‐organisms were detected after 6 months storage in glycerol broth. In the second part of the study nose swabs were suspended in one representative medium (Bacto Nutrient Broth containing 7% glycerol). The mean percentage survival of staphylococci in these suspensions after 1 year's storage at ‐70°C was 75.4%. These results indicate that coagulase‐negative staphylococci in samples of skin flora may be stored under these conditions for long periods, greatly reducing the work‐load in epidemiological studies of infection.