A simple method for determining gentamicin blood levels.

A simple method for the determination of gentamicin blood levels using microbiological bioassay is described. The use of finger tip blood enabled us to test the drug in a number of patients which otherwise would have been difficult. The test is reliable in the presence of other antibiotics in the serum. An assay kit was adapted so that the procedure could be performed and results read by a registered nurse within 6 h and before the administration of the next dose of the drug.