Autoradiography — An Imaging Technique

Autoradiography is an imaging technique that is used to detect radioactive materials. Autoradiography is one of the most important modern cytochemical methods to study the synthesis of molecules and trace the metabolic events in the cells.

This is done by the use of substances labeled with radioisotopes. The most widely used isotopes are tritium (3H), carbon (14C), and phosphorus (32P).

  • Tritium, a carbon labeled thymidine is used for studying the synthesis of DNA
  • Tritium or carbon-labeled uridine is used for the synthesis of RNA
  • Tritiated or carbon-labeled amino acids are used for tracing protein synthesis

Types

Indicative of the type of specimen containing the radioactivity, the kind of emulsion necessary for image formation, and the method of examining the results.

  1. Microautoradiography
  2. Macroautoradiography

This autoradiographic technique contrasts with the techniques such as positron emission tomography (PET) and single-photon emission computerized tomography (SPECT) where the exact 3-dimensional localization of the radiation source is provided by the use of coincidence counting, gamma counters, and other devices.

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