Autoradiography refers to the exposure of photographic films or
emusions by the particles emitted during the decay of radioactive
nuclei. The particles typically responsible for the exposure of the
emulsion are the gamma-ray photons emitted as part of the decay
process, because these particles can travel quite a distance from the
decaying nuclei before they are absorbed. It is also possible to
detect alpha particles (helium nuclei) or beta particles (electrons),
but these particles do not travel very far from the site of the
nuclear decay, and hence the emulsion must be in intimate contact with
the radioactive material being measured,
The discovery of the phenomenon dates back to the 19th century, when
Niepce de St. Victor and Henri Bequerel discovered that uranium salts
and minerals would darken silver iodide and silver chloride emulsions,
leading to the discovery of radioactivity.
If one uses radioactively-labeled compounds in an electrophoresis
experiment, then one can autoradiography to detect the locations of
the labeled compounds on the gel. See
<http://en.wikipedia.org/wiki/Gel_electrophoresis> for an example of
an autoradiographic image of an electrophoresis gel. |
