What are some examples of radioactive isotopes used in research?
Radioactive hydrogen, carbon, phosphorus, sulfur and iodine isotopes are often used in biological research.
Only a limited number of radioisotopes can be used in biological research because they must meet specific qualifications. Most importantly, they have to be elements that naturally occur in the experimental system. Therefore, tritium (hydrogen-3), carbon-14, phosphorus-32/33, sulfur-35 and iodine-125 are often used as radioactive labels / tracers.