Abstract A number of MAG 3-derivatives, containing the three-amide functions modified by inverting the sequence–CO–NH–to–NH–CO–in the first-and/or second-amide functions, have been labelled with 99m Tc in order to study the renal characteristics of the resulting MAG 3-derivatives versus the reference 99m Tc-MAG 3. The 99m Tc-MAG 3-derivatives displayed HPLC-profiles similar to that of 99m Tc-MAG 3. Furthermore, in mice they ...