Our results indicate that the preparation of deuterated macromolecules for neutron scattering from E. coli can be done easily and relatively cheaply. The entry of deuterium into macromolecules of differing species during cell growth can be controlled by varying the D2O content of the medium and the choice of carbon sources, all in minimal medium. Considering the range of deuterations obtainable with simple protonated carbon sources, there seems to be no reason to use deuterated carbon sources except for the rare occasions when a fully deuterated specimen is required.