Autoradiography, Biology

Assignment Help:

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.


Related Discussions:- Autoradiography

Etiologic factor of atherosclerosis, Q. Etiologic factor of atherosclerosis...

Q. Etiologic factor of atherosclerosis? Various factors are responsible for atherosclerosis. These include: 1. Hyperlipidemin: Excess circulating fats in blood especially th

Show the process by which the neural impulse is transmitted, Q. What is the...

Q. What is the mechanism by which the neural impulse is transmitted along the axon? The neural impulse is transmitted along the neuronal membrane through depolarization of cons

Etiologic factor of diabetes, Q. Etiologic factor of diabetes? The prec...

Q. Etiologic factor of diabetes? The precise etiology of diabetes is not known but multiple factors contribute to the disorder. These are reviewed herewith. Type I Diabetes

Overgrazing - degradation of ecosystem, Overgrazing - Degradation of Ecosys...

Overgrazing - Degradation of Ecosystem It refers to the condition when the grazing pressure on the vegetation is so intense that it does not recover. Ultimately, there is a lo

Describe integrative systems of the body, Q. Why is the endocrine system co...

Q. Why is the endocrine system considered one of the integrative systems of the body? What is the other physiological system that also has this function? The endocrine system i

Antimicrobial prophylaxis - number of doses, Timing and number of doses ...

Timing and number of doses It has been common practice to give antibiotics at the time of anesthesia induction, which results in adequate serum and tissue levels of the drugs;

Gastrulation in chick, Gastrulation in Chick Cleavage in the fertilize...

Gastrulation in Chick Cleavage in the fertilized egg occurs during its passage through the oviduct to cloaca of the hen. By the time it is laid meroblastic cleavage has result

What phrase best describes oxidation- reduction reaction, What phrase best ...

What phrase best describes oxidation- reduction reaction? A. phosphoryrylation energezing endergounic reactions b. transferring of electrons from one molecule to another c. shar

Determine about the nervous system and behaviour, Determine about the Nervo...

Determine about the Nervous System and Behaviour Damage to certain parts of the brain will be reflected as behaviour deficits. For example, damage to the temporal lobe may affe

Define water as a source of dietary minerals, Define Water as a source of d...

Define Water as a source of dietary minerals? Although water is composed of only oxygen and hydrogen, the water we drink or use in food preparation can contain significant amou

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd