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Journal of Clinical Microbiology logoLink to Journal of Clinical Microbiology
. 1985 Nov;22(5):835–837. doi: 10.1128/jcm.22.5.835-837.1985

Inoculum size and lot-to-lot variation as significant variables in the tube coagulase test for Staphylococcus aureus.

S T Selepak, F G Witebsky
PMCID: PMC268537  PMID: 3902880

Abstract

For a positive coagulase test with certain isolates of Staphylococcus aureus, inoculation of 0.5 ml of coagulase plasma with at least two colonies and 24 h of incubation at 35 to 37 degrees C may be required. S. aureus does not multiply in coagulase plasma. There is also lot-to-lot variation in the sensitivity of coagulase plasma. On isolates from critical specimens, a negative coagulase test obtained with an inoculum of less than two colonies should be confirmed by repeating the procedure with a larger inoculum or by using some other confirmatory test.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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