Nitrogen-15

Nitrogen-15 is a stable, non-radioactive isotope of nitrogen. It is often used in agricultural and medical research. Nitrogen-15 is frequently used in nuclear magnetic resonance spectroscopy (NMR), because unlike the more abundant nitrogen-14, it has a nuclear spin of one half, which simplifies observation by NMR. Proteins can be isotopical labelled by cultivating them in a medium containing only nitrogen-15. In addition, nitrogen-15 is used to label proteins in quantitative proteomics (e.g. SILAC).

It is a product of oxygen-15 beta decay in stars.

8O15 &rarr; 7N15 + e+ + ν