Stable Bromine and Activation Analysis in Protein Tracer Studies

Abstract

ALTHOUGH the judicious use of radioisotopes such as iodine-131 and iodine-125 for tracing proteins in metabolic studies in man may result in very little iatrogenic exposure of the subject to radioactivity, a general method for labelling such proteins which would not expose the patient to even this small amount of radiation would be preferable, especially in infants and pregnant women. In the present investigation, the feasibility of using neutron activation in the study of the metabolism of proteins labelled with stable bromine, bromine-79 and bromine-81 was explored; the latter isotopes have suitable cross-sections for thermal neutron capture, bromine-79 being activated to bromine-80 (half-life of 4.4 h) and bromine-81 being activated to bromine-82 (half-life of 36 h) (ref. 1).