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
Development of Endosperm In a fertilized embryo sac, the primary endosperm nucleus is generally observed below the zygote. It divides, and further divisions of its products gi


Mouth Inspect and palpate the lips, gums, tongue, palate and oropharynx. Rule out cleft lip and palate, size of chin if small and receding it  shows micrognathia ind

what are the theories of animal classification

What is the stage of the cardiac cycle during which the ventricles are filled? The filling of the ventricles with blood happens during diastole. The Circulatory System - Ima

Bovine rotavirus diarrhoea The bovine rotavirus is a RNA virus with 11 segments of double stranded RNA belonging to the genus Rotavirus in the family Reoviridae. Rotaviruses c

Q. Describe Shunts? Detection, localization and quantification of intracardiac shunts are one of the most important exercises in cardiac catheterization. In most cases a prelim

Q. What is the structure into which the follicle is transformed after ovulation? What is the importance of that structure in the menstrual cycle? The follicle that released the

Endocrine System The nervous system brings about integration and co-ordination of several activities of the animal. The afferent stimuli from several sense organs are brought

ROL E OF NUCLEIC ACIDS - These are DNA / RNA. Unit is nucleotides. Present in viruses and all cells. DNA is concerned as genetic material. RNA as genetic material