Liquid-scintillation counting of 14C-labelled animal tissues at high efficiency

Abstract

The counting of C14-labelled substances, soluble and insoluble in the scintil-lator, at counting efficiencies of 90 and 60% respectively with a single photomultiplier liquid-scintillation-counting assembly operating at room temperature is described. A routine method is described for dissolving tissues and proteins by means of N-potassium hydroxide and a molar solution of Hyamine 10-X in methanol to produce solutions containing 10 mg of dry tissue/ml for liquid-scintillation counting. The use of Hyamine 10-X for blending sources soluble in aqueous solution with scintillator is described. The efficiency of the method was demonstrated by measuring the recoveries of added counts (as [C14] glycine) from tissue and protein solutions. [[epsilon]14]Glycine dissolved in these solutions was counted at the same efficiency as in water solution.