What are 3 ways that radioisotopes can be useful in the study of biology?

Question

What are 3 ways that radioisotopes can be useful in the study of biology?

Answer 1

1. I-135 can be used to label antibodies for radioimmunoassay.

2. Tritium and C-14 labelled precursor molecules can be used to study macromolecule synthesis: methione for protein synthesis, uracil for RNA synthesis, thymine for DNA synthesis.

3. Labelled molecules such as drugs can be used to study their metabolism in the body.

Answer 2

They can be used to date old samples (Carbon-14).

They are used extensively to track the metabolism and movement of molecules in biological systems.  For example, I use RNA probes labeled with S35 to locate specific mRNAs within tissue samples.  Radioisotopes of Phosphorus and Iodine are also used extensively in biology.  

Someone else think of a third way.  Or divide my second into a few different uses.

Answer 3

There's definitely more than three uses for radioisotopes.

1. Archaeological Dating. Carbon-14 is often used to find the age of a substance many years old.

2. In the use of x-rays and cat scans. X-Ray technicians often inject radioactive iodine in ones system to increase the contrast between soft tissue and bone on an x-ray image.

3. Smoke detectors: Americium is often used in smoke detectors because it is very sensitive to burning carbon dioxide.

4. Pest Control: Some radioactive isotopes are used to control med flies in homes.

5. Agriculture: Radioactive elements can be replaced with elements in plants to trace the use of that particular element.

Hope this helps.