radiolabelling is radiolabel's Present Participle

radiolabel

Plural Form：radiolabels Past Participle：radiolabeled Present Participle：radiolabeling Present Participle：radiolabelling Past Participle：radiolabelled

E-E

n.	1. a radioactive substance attached to another substance as a means of tracing the location or tracking the movement of that substance.
v.	1. to attach a radiolabel to a substance