Autoradiography

Autoradiography (autoradiography, radioautography) - a method of obtaining a photographic image of an object by means of influence on a photosensitive emulsion radiation from this object contains radioactive substances. In medicine and biology method autoradiography used to detect small amounts of radioactive isotopes and study their distribution in the slices of whole organs or tissues and in individual cells.

Autoradiography (radioautography, or an autoradiograph) - method image materials, in particular tissues of living organisms, using the commit radiation contained radioactive substances. A. indispensable in cases of detention of small amounts of radioactive element, whose strength is not measured by meters. Autoradiography allows you to explore the distribution of radioactive elements in the slice of tissue, the nature of removing this element from the body (Fig. 2) and its accumulation in different body systems.
There are contrasting and trace autoradiography. At first the cut fabric is brought into contact for a while with the emulsion to get on the print. On the character of distribution and the quantity of radioactive elements in the slice judged by optical density blackening of fotosela determined using photometry.
When tracking a form of radiation and the number of the element is judged by counting the number of tracks in the region (under the microscope).
Modification A. - gistiotitarnaya in which a tissue section, brought into contact with a nuclear emulsion with it manifests itself, is fixed and stained. In contrast to autoradiography method has a high resolution. In experimental studies gistiotitarnaya used to investigate processes at the cellular level. In the clinic it allows you to determine the radioactivity of blood (Fig. 1), lymph nodes and other Morphological study in combination with gistiotitarnaya allows one drug under the microscope to study the localization of radioactive elements in the subtlest structures of tissues, cells (Fig. 3), the nature of the tissue damage in places deposition of these elements (Fig. 4), their quantitative distribution based on counting the number of tracks or the grains of silver halide in a particular area, but the length and shape of the track is to identify the nature of the radiation. Tracks alpha-particles straightforward, beta-particles - zigzag, 'radiation gives the General background. Clear images with high resolution depends on the quality of the emulsion, and meticulous preparation thin slice, thoroughness of compliance with the minimum distance between the cutting emulsion and muscle releases and tendon transfers exposure.
For contrast autoradiography optical and nuclear emulsion, for tracking A. - nuclear plates type MP, to gistiotitarnaya α-emitting materials - nuclear plates of type a-2 or MP, emulsion And R. In the study β-emitting materials used plates type MP or MK, emulsion R. These emulsions are used for microbiological and other studies.

Fig. 1. Getoutdirname smear the blood of the dog: the tracks of alpha-particles Ro210 in the plasma (the method of liquid emulsion).
Fig. 2. Autoradiogram kidney rats; the highest density blackening of emulsion on the site of contact papilla body shows good breeding Sr90, a day after it gets to the organism (accent autoradiography).
Fig. 3. Getoutdirname of histiocyte: a collection of tracks alpha-particles Ro210 in the cytoplasm (the method of liquid emulsion).
Fig. 4. Getoutdirname thigh bones of rats. The accumulation of Pu -239 in the cells of angosta and periosteum. Mounted method.