radiolabel

From radio- +‎ label.

radiolabel (third-person singular simple present radiolabels, present participle radiolabeling or radiolabelling, simple past and past participle radiolabeled or radiolabelled)

1. To tag a substance (especially a biological substance) with a radioactive tracer

radiolabel (plural radiolabels)

1. A radioactive tracer; a radiotracer