when exposed to hela cells in tissue culture for 72 hr. , antimicrobials could be categorised into three groups characterised by cell associated concentrations much lower ( ampicillin , cephalexin , cloxacillin , flucloxacillin , streptomycin and trimethoprim , all 14 % or less ) , much higher ( tetracycline and polymyxins ) or approximating to those extracellularly ( erythromycin , lincomycin , fusidic acid and gentamicin ) .
C1136254
antimicrobials
C0039644
tetracycline