title: A new bioassay method for quantitative analysis of tetracyclines.
abstract: A new method is described for quantitative analysis of tetracycline, based on the decrease in external pH of bacterial suspensions after the addition of a glucose pulse. The decrease in external pH of these suspensions was inversely proportional to the concentration of tetracycline. The correlation coefficient of standard response lines derived from the bioassay was 0.99. Tetracycline potency was determined in six tetracycline HCl samples by the sugar pulse bioassay and a turbidimetric method. The turbidimetric assay result varied from the glucose-pulse data by no more than 7 and 3% at 3 and 7 min, respectively. The procedure is rapid, precise and quantitative, and requires minimal preparation and use of media, with savings in laboratory resources and time.
authors.affiliation: Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Avda. Joan XXIII s/n, 08028, Barcelona, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Rodriguez
authors.forename: Sònia
authors.initials: S
authors.lastname: Roig
authors.forename: Núria
authors.initials: N
authors.lastname: Olmedo
authors.forename: José G
authors.initials: JG
authors.lastname: Lorén
authors.forename: Núria
authors.initials: N
authors.lastname: Rius
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000494:pharmacology; D001681:Biological Assay / Q000379:methods*; D003470:Culture Media / Q000737:chemistry; D016983:Enterococcus / Q000187:drug effects / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009391:Nephelometry and Turbidimetry; D013754:Tetracyclines / Q000032:analysis* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D013754:Tetracyclines; D005947:Glucose