Fig. 3. Preparation and use of the kit formulation for [⁸⁹Zr]Zr-oxine, [⁶⁴Cu]Cu-oxine and [⁶⁸Ga]Ga-oxine.

8-hydroxyquinoline is dissolved in water, followed by addition of HEPES and polysorbate 80 and pH adjustment to 7.9-8.0 with concentrated NaOH. This solution can be divided into single-use aliquots, e.g. one patient dose, and radiolabelled with commercial zirconium-89, copper-64 or gallium-68 as and when required. Alternatively, a central radiopharmacy facility could provide the radiolabelled product to the site performing the cell radiolabelling. The formulated [⁸⁹Zr]Zr-oxine (or [⁶⁴Cu]Cu-oxine/[⁶⁸Ga]Ga-oxine) can be used to radiolabel various cell types, such as granulocytes or T-cells, without any further steps, for PET imaging.