Assay of tritium and carbon-14 in animal tissues by liquid scintillation

1. 1. Mouse organs are digested in hyamine hydroxide methanolic solution and the digest is diluted with dioxane before the addition of a toluene scintillating solution. 2. 2. The vials ready for counting contain up to 155 mg of fresh tissue in a volume of 16 ml. 3. 3. Without digest, with the Packard Tri-Carb spectrometer, the yields of counting of the final scintillating mixture are 50% for 14C and 17.5% for 3H. With 100 mg of stomach, intestine, brain or muscle, the yields are 40% for 14C and 5% for 3H. They are half these values with 100 mg of liver, lung or heart. 4. 4. The chemiluminescence with the Tri-Carb spectrometer is negligible with 14C, but a waiting period of 48 h is necessary for counting 3H. During this time, the vials can stay at room temperature without particular screening from the light. © 1963.