isotoppimerkinnöillä

Isotoppimerkinnöillä, also known as isotopic labeling, is a technique used in various scientific fields to trace the pathway of atoms or molecules within a biological system, chemical reaction, or geological process. This is achieved by replacing one or more atoms of a specific element with one of its isotopes, which have the same number of protons but a different number of neutrons. These isotopes are typically stable or radioactive.

Stable isotopes, such as deuterium (hydrogen-2), carbon-13, or nitrogen-15, are detected using mass spectrometry or nuclear magnetic resonance (NMR) spectroscopy. Radioactive isotopes, like tritium (hydrogen-3), carbon-14, or phosphorus-32, can be detected using scintillation counting or autoradiography. The chosen isotope depends on the element being studied and the sensitivity required for detection.

In biological research, isotopic labeling is crucial for understanding metabolic pathways, drug absorption and distribution, and protein synthesis. For example, administering a drug containing carbon-13 allows researchers to track its movement through the body and identify its breakdown products. In chemistry, it helps elucidate reaction mechanisms by following the fate of specific atoms during a transformation. Geologists use stable isotopes to study climate change history, understand rock formation processes, and trace the origin of water sources. The principle relies on the fact that the labeled atoms behave chemically identically to their natural counterparts but can be distinguished by their mass or radioactivity.