The gallium-deferoxamine complex: stability with different deferoxamine concentrations and incubation conditions.

Previous studies report that deferoxamine (DFO) binds metallic ions such as Fe3+, In3+ and Ga3+ with very high affinity. This property of DFO has been utilized to label DFO-coupled compounds with radiometals such as 67Ga and 111In. We have studied the effect of low DFO concentrations and of different incubation conditions on the stability of the 67Ga-DFO complex. In our experience high (> 5 microM) DFO concentration appears to be critical in obtaining high radiochemical purity of such complexes.