Appeal No. 1997-2743
Application No. 08/442,252
order “to establish an effective oxidation potential of the Tc(II) thus providing the necessary
redox potential for in vivo oxidation,” four of the ligands “use phosphorous, arsenic, or
nitrogen as ligating atoms,” while “[t]he remaining two ligands use sulfur or selenium to
complex to the Tc center.” Abstract. Deutsch describes kits comprising phosphine salts
bound to HCl, H SO , iron(II), copper(I) or zinc(II), but makes no mention of stabilizing
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agents.
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Woulfe also describes Tc -phosphine complexes, as well as kits comprising a
phosphine salt bound to copper(I), and ascorbic acid as an anti-oxidant.
The examiner acknowledges that Feld does not disclose phosphine, arsine, thiol,
thioether or isonitril ligands, but concludes that “it would have been obvious to employ in
the [Deutsch] or [Woulfe] kits the cyclodextrin stabilizers disclosed by [Feld] since all three
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references teach Tc labeled diagnostic ligands and kits,” while “[d]etermining optimum
amounts of copper salt, ascorbic acid, ligand and sodium carbonate buffer would have
amounted to optimization of reactant concentrations . . . and would have been routine
experimentation for one of ordinary skill in the art.” Examiner’s Answer, paragraph 11(a).
If we understand the rationale underlying the examiner’s rejection correctly, it is simply that
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all “Tc labeled diagnostic ligands,” regardless of structure or other properties, are
essentially interchangeable, and it would have been obvious for one skilled in the art to
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stabilize any Tc ligand with any one of the many stabilizers disclosed by Feld.
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