Radiolabeling

Definition

The technique of incorporating a radionuclide into a molecule to track its metabolic fate, distribution, or transformation through biological systems; the radioactive analog of isotopic labeling. In arthropod research, radiolabeling enables quantitative tracing of compounds that cannot be followed by conventional chromatographic or spectroscopic methods alone.

Etymology

From Latin radius (ray, spoke) + label (marker, tag) + -ing (process suffix), reflecting the use of radioactive decay emissions as detectable markers.

Example

To map the biosynthetic pathway of the bark beetle aggregation pheromone ipsdienol, researchers fed de novo-synthesized [1-¹⁴C]mevalonate to male Ips pini and tracked radiolabel incorporation into the final terpenoid product via scintillation counting of gland extracts.

Synonyms

• radiotracing
• radioactive labeling

Related Terms

• isotopic labeling
• scintillation counting
• Autoradiography
• metabolic tracer
• radioisotope feeding experiment
• stable isotope analysis

Usage Notes

Distinguished from stable-isotope labeling by the use of radioactive rather than non-radioactive isotopes; requires specialized handling, shielding, and disposal protocols. In entomology, common applications include measuring nutrient assimilation efficiency, quantifying pheromone production rates, tracking pollen or prey consumption, and estimating field dispersal distances via mark–release–recapture with radiolabeled individuals. The term 'radiotracer' emphasizes the labeled compound itself, while 'radiolabeling' emphasizes the methodological process.