Autoradiography

Definition

Autoradiography is a technique that uses radioactive isotopes to visualize molecules or fragments of biological samples, such as DNA, RNA, or proteins. It produces an image on photographic film or a digital sensor by detecting emitted radiation.

5 Must Know Facts For Your Next Test

1. Autoradiography is used to detect and analyze the distribution of radioactive substances within a sample.
2. Commonly labeled molecules in autoradiography include DNA, RNA, and proteins using isotopes like phosphorus-32 (32P) or sulfur-35 (35S).
3. It is frequently employed in molecular biology to study gene expression and the location of specific nucleotide sequences.
4. The process involves exposing the biological sample to a photographic film; areas where radioactive decay occurs appear as dark spots on the developed film.
5. Autoradiography can be combined with other techniques such as gel electrophoresis for more detailed molecular analysis.

Review Questions

• What types of molecules are most commonly visualized using autoradiography?
• How does autoradiography produce an image on photographic film?
• Which radioactive isotopes are typically used in autoradiography for labeling DNA?

Related terms

Gel Electrophoresis: A technique for separating nucleic acids or proteins based on their size and charge.

Radioactive Isotope: An isotope whose nucleus decays spontaneously, emitting particles and energy.

Northern Blotting: A technique used to detect specific RNA sequences in a sample.