Production of no-carrier-added 199Au for gold cluster-labelled antibodies.

The production of no-carrier-added (NCA) 199Au by neutron activation of 198Pt was developed and the radiochemical separation of 199Au from Pt targets was investigated. Three different procedures, based on anion exchange in mixed solvent media, solvent extraction and extraction chromatography, are reported. The extraction chromatography method was superior in terms of yield (> 95%), Pt separation factor (< or = 10(-5)), and separation time (approximately 1 hr). This scheme has been used to successfully process large amounts (> 30 GBq) of 199Au, with an average specific activity of 7.59 GBq/micrograms (205 mCi/micrograms).