Evaluation of serum gentamicin assay procedures for a clinical microbiology laboratory.

Four methods for the measurement of serum gentamicin concentration were evaluated with respect to cost-effectiveness, accuracy, and precision. Gentamicin concentration was determined in 112 clinical samples by the Staphlococcus epidermidis agar diffusion bioassay procedure in routine service in our laboratory at the time this study was initiated. Appropriate portions of these clinical samples were frozen and later thawed for remeasurement of gentamicin by bioassay or for measurement of gentamicin in one of three other systems. These included the Enzymatic Radiochemical Assay, the Diagnostic Products Corporation Radioimmunoassay and the New England Nuclear Corporation Radioimmunoassay. In addition, gentamicin dissolved in horse serum at 2, 4, 6, 8, 10, and 12 micrograms/ml was aliquoted, frozen, and later thawed for assay in each of the above systems. The data were analyzed for evidence of constant and proportional bias as well as for accuracy and precision.

Microbiology subsystem of a total, dedicated laboratory computer system.

The computer system used by the Microbiology Service of the Clinical Pathology Department, Clinical Center, National Institutes of Health is discussed. This microbiology subsystem is a part of a dedicated on-line laboratory computer system used by the entire department. The laboratory computer is connected on-line to a hospital computer which provides patient admission, transfer, and discharge data. Mark sense worksheets and cathode ray tube terminals are used for result entry and correction. Cumulative patient reports are printed. Results for both active and completed accessions can be easily retrieved on cathode ray terminals in the laboratory. All laboratory data are archived on magnetic tape from which a research data base and microfiched laboratory records are generated. The manner in which the system is integrated in the routine operation of the microbiology laboratory is emphasized. In addition, some of the costs, benefits, liabilities, and pitfalls associated with the introduction of the computer in the laboratory are reviewed. Finally, we have presented our concept of some of the future enhancements to our present system and some of the directions in which any future microbiology system might develop.