irect labelling method and conditions of monomeric antibody Fab’ with 99mTc were investigated. Polyclonal antibody IgG was digested with ficin to produce dimeric fragments F(ab’)2
which was subsequently reduced to monomeric fragments Fab’ with 2-mercaptoetylamine. Finally
Fab’ was incubated with sodium gluconate(Sn(Ⅱ)) kit solution and 99mTc
eluated at room temperature to form 99mTc-Fab’.The labelling efficiency was 85%- 95%. The stability of labelled products was satisfactory and the elimination rate was faster than 90mTc-IgG.