How are molecules labeled?

How are molecules labeled?

There are two main methods of marking nucleic acids. One requires the use of nucleic acid monomers (DNA or RNA), nucleotides, made radioactive. These are incorporated by the cell into the newly synthesized nucleic acid strands and make them radioactive.

How to recognize a DNA fragment?

A single strand ofDNA is shown. Sequence differences are noted in red. The restriction enzyme (symbolized by a blue scissor) recognizes the GACC sequence and cuts between A and C. After cutting, electrophoresis makes it possible to separate the fragments depending on their size.

How to read a gene sequence?

For that, he must start from the bottom. If the smallest piece ofDNA comes from the tube band C, it notes a C. If the second shortest end ofDNA comes from the band of the G tube, it then notes a G and so on until all the letters of the gene have been read.

How to recognize the principle of radioactive labeling?

the marking isotopic or radioactive marking is a technique used to follow the passage of an isotope (an atom with detectable variations) during a reaction, a metabolic pathway or in the cell. The compound is “tagged” by replacing specific atoms with their isotopes.

What is a DNA fragment?

A gene is a DNA fragment, therefore a portion consisting of a sequence of nucleotides. There are 4 nucleotides: A, T, C and G. A gene contains coded information: it is the order in which the nucleotides are linked which determines this information within a sequence ofDNA called gene.

How to detect radioactive material?

Geiger-Müller counters have been designed to allow the observation of the various radiations of natural or artificial radioactivity which can be classified into two main categories: charged particles (electrons, positrons, protons, alpha, etc.) and neutral particles ( neutrons, gamma, neutrinos).

How to date a radioactive sample?

For date a sampleyou have to start by choosing the isotope radioactive to be used according to age to be determined. This age must be between one hundredth and ten times its half-life. Beyond that, all the nuclei have been disintegrated and any measurement is impossible!

What are the steps of the RFLP technique?

Steps of the RFLP technique: DNA extraction, hydrolysis of DNA by a restriction enzyme, separation of restriction fragments by electrophoresis on agarose gel, denaturation of DNA with sodium hydroxide to obtain single-stranded DNA , membrane transfer, reinforcement of fixation.

What is the RFLP technique?

This technique is used for carrying out genetic fingerprints and in paternity tests. Stages of the RFLP technique: transfer onto membrane, reinforcement of fixation. visualization of the fragments by hybridization with a probe. The DNA of an individual or a cell is first extracted and purified.

What is the difference between RAPD and RFLP?

RAPD and RFLP are important markers used in molecular biology. Both methods are capable of detecting genetic variation among organisms. RAPD is performed using random primers. RFLP is performed using specific restriction enzymes.