Premium
A METHOD FOR ESTIMATING LOW CONCENTRATIONS OF DIFFUSIBLE PENICILLINASE
Author(s) -
HEDGES A. J.
Publication year - 1960
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.1365-2672.1960.tb00201.x
Subject(s) - penicillin , diffusion , chromatography , chemistry , agar gel , agar , analytical chemistry (journal) , biology , biochemistry , antibiotics , microbiology and biotechnology , physics , thermodynamics , genetics , bacteria
SUMMARY A method suitable for the assay of low concentrations of diffusible penicillinase has been developed and its technique is described. The concentration of soluble penicillinase in a sample is estimated by comparing its rate of diffusion in an agar gel with that of a standard preparation, the extent of diffusion being detected, after a fixed period, by a microbiological method employing ‘zones of exhibition’. The method enables four similar samples to be compared on a single large plate in the form of a randomized Latin Square. Under these conditions a concentration of penicillinase able to inactivate only 2 units of penicillin/ml/hr was measurable with an experimental error (95% confidence interval) of c. ±10%.