Autoradiography, Biology

Autoradiography

Autoradiography is a modification of the radioactive tracer technique. In this technique, the radioactivity is detected by a thin film of photographic emulsion containing silver compounds which is put over a labelled cell or tissue. The rays emitted by radioisotope from the cell or tissue expose the photographic emulsion like a photographic film which is developed in a dark room. Silver grains are seen as black dots on parts of the specimen where radioisotope is accumulated.

Autoradiography reveals the metabolic processes of the cell. For example, by labelling cells with 3H thymidine, it is found that silver grains are localised in nucleus, which shows that DNA is synthesised in the nucleus. Similarly, by labelling cells with 3H uridine, silver grains are first seen in nucleus and then after some time these grains appear in the cytoplasm. This clearly demonstrates that RNA is initially synthesised in the nucleus but later on migrates to the cytoplasm.

Different radioisotopes are used for localising different macromolecules. As stated earlier,  cells are labelled with 3H thymidine for the studX of DNA metabolism, 3H uridine to study RNA metabolism, tritiated amino acids for examining the synthesis of proteins, treated monosaccharides such as 3H-mannose and 3H-fucose for examining the synthesis of polysaccharides.

Posted Date: 12/10/2012 1:11:12 AM | Location : United States







Related Discussions:- Autoradiography, Assignment Help, Ask Question on Autoradiography, Get Answer, Expert's Help, Autoradiography Discussions

Write discussion on Autoradiography
Your posts are moderated
Related Questions
Define the interaction of vitamin c with lead and mercury? Vitamin C, lead and mercury: Iron alleviates lead toxicity but ascorbic acid is ineffective. Ascorbic acid alleviat

Define Distribution of body iron in different compartments? In humans, the total quantity of iron in the body varies with haemoglobin concentration, body weight, gender and the

How much Fluids should be taken for management of obesity? Liberal amounts of water and zero/low calorie fluids may be included in the diet. It may be helpful to have a glass o

Q. What do you mean by Polyphagia? Increased Hunger (Polyphagia): As patient is losing more sugar in the urine, he feels hungry very soon and tends to take more food. It is cal

Define classification of carbohydrates - Oligosaccharides? Oligosaccharides are short chains of saccharide units and are condensation products of three to ten monosaccharides.

Q. Why is the sun the "motor" of the water cycle? The sun can be considered the motor of the water cycle for the reason that upon its energy the transformation of liquid water

Q. What are the organs that are part of the female reproductive system? The organs that constitute the female reproductive system are the ovaries, the uterus, the Fallopian tub

Q. After the morula stage what is the next stage? What is the morphological feature that defines this stage? In the blastula stage the compactness is lost and an internal cavit

Cryptococcosis An opportunistic infection, caused by Cryptococcus neoformans is affecting immunocompromised individuals mainly with impaired cell mediated immunity. The disease

Explain the effect on Minerals of the Human milk? There appears to be no relationship between dietary intake and concentrations in milk for copper, iron or zinc. Iron supplemen