Radioactive labelling, Biology

Assignment Help:

Radioactive Labelling

Radioactive labelling method has been effectively applied on the chick blastoderm. The method includes labelling one embryo (donor) and grafting a part of it in similar position on another unlabelled embryo of similar stage (Host). An explanted blastodermis immersed in a medium consisting of the radioactive mtiated (H3) thymidine. In 3 to eight hours the tritiated thymidine is incorporated into the chromosomal DNA of dividing blastodermal cells. The embryo labelled in such type of a way by tritiated thymidine serves as a donor. Another embryo at similar stage of development as attained through the labelled donor in the meantime is then chosen to serve as the host. A small area of the host embryo is excised and replaced by a corresponding piece from the donor of which the fate is to be determined. Healing generally takes place quickly and the development is not impaired if the operation has been done carefully.

The thymidine does not pass out of the nuclei of the labelled cells but stays in the chromosomes of their descendents. Even though the radioactive thymidine present in the DNA is gradually diluted with each subsequent chromosomal replication radioactivity remains for a considerable time. Such type of composite embryo (partly from donor and partly from the host) is tested at a later stage of development for radioactivity through special techniques like autoradiography etc. Only the part(s) or structure(s) developed from the grafted piece display the presence of radioactivity thus establishing the fate of specific area taken from the donor.


Related Discussions:- Radioactive labelling

Hounsfield units of computed tomograpy scan, Hounsfield Units: It is an...

Hounsfield Units: It is an arbitrary scale of gray values for CT. It is an indicator of bone density: - Trabecular bone has a range of 200 - Cortical bone has a range

What are the parts of nervous system, What are the parts of Nervous system ...

What are the parts of Nervous system Nervous system is divided into three main parts: 1) The brain and spinal cord or Central Nervous System (CNS). 2) The nerves or Peri

Polysaccharides, PO L YSACCHARIDES Polysaccharides are complex car...

PO L YSACCHARIDES Polysaccharides are complex carbohydrates. Polysaccharides are also called glycans. These are insoluble in water. Polysaccharides are not swee

Discuss the genetics involved in the inheritance, Casein is the main protei...

Casein is the main protein in milk. There are three types of casein, one of which is beta casein. Beta casein comes in two main variants called A1 and A2. The order of amino acids

Shifting attention by dopamine, Q. Shifting attention by Dopamine? Dopa...

Q. Shifting attention by Dopamine? Dopamine: Dopamine plays a pivotal role in aspects of shifting attention. Administration of D1/D2 receptor antagonist haloperidol impairs the

How does vitamin c act in the body, Q. How does vitamin C act in the body? ...

Q. How does vitamin C act in the body? What is the harm caused by insufficiency of vitamin C? Why was this deficiency also known as "sailors' disease"? Vitamin C, or ascorbic a

Viruses, are viruses cellular organisms

are viruses cellular organisms

Invertebrates, Are chaetopterus species coelomate?

Are chaetopterus species coelomate?

Define about the paper chromatography, Define about the Paper Chromatograph...

Define about the Paper Chromatography? Paper chromatography is a very useful technique for separating mixtures of metal ions, anions, amino acids, sugars, dyes, drugs, etc. The

The warmest parts of the body?, What are likely to be (a) the coldest, (b) ...

What are likely to be (a) the coldest, (b) the warmest parts of the body? The extremities of the body (hands and fingers, feet and toes, ears and nose) are likely to be the col

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