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

Infectious diseases, what are pathogenic characteristics of protoctista?

what are pathogenic characteristics of protoctista?

What is digestion, What is digestion? Digestion is the breaking down of...

What is digestion? Digestion is the breaking down of larger organic molecules obtained from the diet, e.g. carbohydrates, fats, proteins, into smaller ones, as glucose, fatty a

What is ancient gondwanaland, What is Ancient Gondwanaland? Did you kno...

What is Ancient Gondwanaland? Did you know that the land surface of the earth was once comprised of two super continents called Gondwana and Laurasia? Click on the Multimedia b

Which kind of circulatory system do molluscs have, Q. Which kind of circula...

Q. Which kind of circulatory system do molluscs have? How can it be compared to the respiratory system of annelids? Molluscs, with the exception of cephalopods, have an open ci

Suberin, SUBERIN It is a lipid formed by esterification of phellonic ac...

SUBERIN It is a lipid formed by esterification of phellonic acid or its derivative with glycerol. Suberin occurs in the walls of cork cells and endodermal cells. It makes

Define the contraceptive morbidity, Define the Contraceptive Morbidity ...

Define the Contraceptive Morbidity Contraceptive morbidity, which covers any condition that result from efforts (other than abortion) to limit fertility, whether they are tradi

Ability of mammalian kidney, Normal 0 false false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Define briefly about the seed proteins, Define briefly about the Seed Prote...

Define briefly about the Seed Proteins? Although a large number of plants produce seeds having protein contents in excess of 15%, only a few are utilized for food, eg. soybean,

Explain about the secondary protein derivatives, Explain about the Secondar...

Explain about the Secondary Protein Derivatives? These are the products of further hydrolytic cleavage of the protein molecule, Examples include: a) Proteoses: Soluble in wa

Types of passive transport, Simple diffusion Only comparatively small u...

Simple diffusion Only comparatively small uncharged or hydrophobic molecules (H2O, O2, and CO2, other gases, urea and ethanol)   cross   the lipid   bilayer   through simple

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