Errors in the Estimation of Streptomycin in Serum.

In the report on specific laboratory tests in streptomycin therapy oftuberculosis (Medical Research Council, 1948) a subcommittee of the Medical Research Council recommended two techniques for the estimation of streptomycin in serum. One of these was a method involving serial dilutions in a serum-glucose-phenol-red indicator system on a waxed slide, followed by incubation in capillary tubes. The other was an agar diffusion technique carried out in small diameter tubes. An attempt has been made to assess the errors involved in using these two techniques under laboratory conditions similar to those in which they will actually be used.