In solution Cu-64 is usually in divalent state. It can be radiolabelled with macrocyclic chelators. DOTA is being used, but other, specific copper chelators such as MeCOSar may provide improved stability .
Cu-64 decays with a half-life of 12.70 h by positron emission (17.6%) or electron capture (43.9%) to stable Ni-64 and by beta-minus emission (38.5%) to stable Zn-64 respectively. The emitted positrons have 278 keV average energy and 653 keV maximum energy and the emitted low energy beta-minus spectrum has 191 keV average energy and 579 keV maximum energy.
Cu-64 emits only one weak gamma-ray at 1345.8 keV (0.48%).
Cu-64 can be produced by different methods , e.g. proton irradiation of enriched Ni-64 targets at Hevesy Laboratory at DTU, C30 cyclotron at NCBJ and INJECTOR 2 at PSI or deuteron irradiation of enriched Ni-64 targets at ARRONAX. In addition, low-specific activity (>0.1 GBq/mg) Cu-64 is produced at NCBJ by irradiating enriched Cu-63 targets in the MARIA reactor.
The radiochemical separation is performed at the same laboratory where the irradiation took place. Activity will be shipped from there to the users in solution or in form of a dried deposit respectively.
The specifications given here are the ones for production at Hevesy lab (DTU, Risø, Denmark). The characteristics of the produced Cu-64 varies for the other suppliers (ARRONAX, Nantes, France; PSI, Villigen, Switzerland; NCBJ, Otwock-Swierk, Poland), and the best solution for a given project will be discussed between PRISMAP and the users.
|Daughter||Stable Ni-64 and stable Zn-64|
|Branching Ratio/Decay||17.6% β+, 43.9% EC, 38.5%β-|
|Purification||single step cation exchange chromatography|
|Chemical Form||Dry CuCl2|
|Specific Activity||>500 GBq/µmol at end of chemistry (measured by ICP-OES)|
|Radionuclidic Purity||>99% (Co-56, Co-57, Co-58 each below 0.01%)|
|Chemical Purity||Metal impurities and copper contents determined by ICP-OES for each batch: Ni, Zn and Fe each <1 µg/GBq|
|Identification||1346 keV gamma line and 511 keV annihilation gammas present|
|Appearance||Invisible deposit at bottom of glass vial|
|Activity available||1-10 GBq|
|Availability||Dispatch of batches 1-3 GBq every Tuesday and Thursday 09:30 AM. Larger batches up to 10 GBq on request.|
|Grade||Preclinical grade or GMP (as labelling intermediary, however no PhEur monograph exists), n.c.a.|
|Other information||Product is normally shipped in dry state, in “empty vials” but ready for reconstitution with what buffer the user prefers, and then ready for labelling of e.g. DOTA-compounds. Upon request, product can be shipped in 0.05 M HCl (1-2 ml) or Ammonium Acetate buffer (1 M, 1-2 ml). Bioburden and endotoxin burden can be analysed post release, upon request.|