The task of the work was indium-111 radiolabelling of a new conjugate of pyridin-N-oxid-derivative DOTA, 10-[(4-carboxy-1-oxidopyridin-2-yl)methyl]-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (H3DO3ApyNO-C)] with PAMAM dendrimer of fourth generation (D-G-4h) containing 64 amino groups on its surface, quality control and characterization of radiolabelled product for consequent pharmacokinetic studies.