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Antimicrobial Agents and Chemotherapy logoLink to Antimicrobial Agents and Chemotherapy
. 1972 Feb;1(2):94–99. doi: 10.1128/aac.1.2.94

Microiodometric Determination of β-Lactamase Activity

R B Sykes a, K Nordström a,1
PMCID: PMC444175  PMID: 4618455

Abstract

The product of β-lactamase activity (a penicilloic acid in the case of a penicillin) is stoichiometrically oxidized by iodine. Hence, the β-lactamase activity can be measured as decolorization of the blue starch-iodine complex. Since the decolorization is a slow process, the rate of decolorization gave an underestimate of the rate of penicillin hydrolysis until a steady state was obtained after 15 to 20 min. If the reaction mixture (3 ml) contained no more than 0.001 unit of enzyme, a correct determination of β-lactamase activity was obtained from the microiodometric method described. The method is sensitive and some applications are mentioned.

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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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