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March 1966

Levels of Penicillin in Serum of Newborn Infants

Author Affiliations

From the Pediatric Service, the Thorndike Memorial Laboratory, and the Second and Fourth (Harvard) Medical Services, Boston City Hospital; the departments of pediatrics, Boston University School of Medicine; and the departments of pediatrics and medicine, Harvard Medical School, Boston.

Am J Dis Child. 1966;111(3):267-271. doi:10.1001/archpedi.1966.02090060077006

SERIAL determinations of antibiotic activity in the serum of infants have been limited by the relatively large amounts of serum required by the tube-dilution method of Rammelkamp.1 The micromethod to be described is a modification of the Rammelkamp technique but is more rapid and requires only 0.025 ml of serum per test. This method makes use of a microtitration system similar to that described by Sever2 for serological investigations of viral infections. The results of its application to a study of the levels of penicillin G after single intramuscular doses given to infants 4-hours to 1-month old will then be presented.

Materials and Method  A Micromethod for Assay of Penicillin in Serum of Infants.Materials:

  1. Microtitration system.

    1. Dilution plates

    2. Wire loops

    3. Pipette droppers

    4. Capillary tubes and bulbs

    5. Blotters

    6. Plastic tape

  2. Capillary tubes for collecting serum

  3. Screw cap vials