Kit for radiolabelling

A method for radiolabelling a chelate-functionalized targeting agent with gallium-68, comprising

• recovering an eluate of a gallium-68 generator into a first vial located within a self-shielded device;
• adding a suitable amount of acetate buffer to a second vial comprising a lyophilized chelate-functionalized targeting agent and a lyophilized metal inhibitor to form a mixture comprising acetate buffer, chelate-functionalized targeting agent and metal inhibitor, wherein the acetate buffer is added in a suitable amount to balance the pH of the eluate from the gallium-68 generator to a pH value ranging from 3 to 5 when the mixture is contacted with the eluate;
• recovering the mixture of acetate buffer, chelate-functionalized targeting agent and metal inhibitor from the second vial;
• adding the mixture of acetate buffer, chelate-functionalized targeting agent and metal inhibitor to the recovered eluate of the gallium-68 generator in the first vial located within the shielding device;
• and
• allowing radiolabelling of the chelate-functionalized targeting agent with gallium-68,
• wherein said metal inhibitor is selected from the group consisting of:
• DOTA, glucose, fructose, beta-cyclodextrin, D-mannose, and tetra-tBu-DTPA, and
• wherein said chelator in said chelate-functionalized targeting agent is selected from the group consisting of:
• NOTA, NODAGA, HBED and DFO.