On the preparation of 80Br-biomolecules

The effect of several experimental parameters on the efficiency of the 80Br incorporation via the 'CF3sup(80m)Br-KBr03' gas exposure resulting in carrier free radiobrominated compounds was investigated by using two model compounds, L-tyrosine and guanosine. The 80Br labelling proceeds very rapidly in the case of the L-tyrosine and is fairly independent of 'labelling time' and substrate concentration as long as a certain minimum amount of L-tyrosine is used. This is in contrast to the guanosine system where rapid secondary reactions reduce the initially high yields of 80Br-8-bromoguanosine at extended 'labelling times' and where large amounts of substrate are needed to produce optimum yields. (author)