To investigate the distribution properties of total radioactivity (all test item related material).
Typically in mice or rats.
Animals are administered with the radio-labeled test item (typical labels: 3H or 14C).
At scheduled time-points selected organs/tissues are autopsied.
The weight of the isolated matrices are measured, the samples are homogenized, solubilized and the total radioactivity is quantified by liquid scintillation spectroscopy.
For 3H: checking of the potential loss of label due to tritium-proton exchange
Evaluation of the total radioactivity: