Molecular biology - Molecular Biology. Molecular biologist polymerase chain reaction

Molecular biology / m ə. l.ɛ toJ.ʊ l.ər. / It is a branch of biology, as regards the molecular basis of biological activity between biomolecules in various cell systems, including the interactions between DNA, RNA, proteins and their biosynthesis, as well as the regulation of these interactions. Write B. nature In 1961, Astbury described the molecular biology:

Not so much technique as an approach, an approach from the point of view of the so-called fundamental sciences with the leading idea of \u200b\u200bfinding below large-scale manifestations of classical biology for the corresponding molecular plan. He is concerned in particular, with forms Biological molecules and [...] mostly three-dimensional and structurally - which does not mean, however, that this is just a clarification of morphology. It must at the same time explore the genesis and functions.

Attitude to other biological sciences

Researchers in the field of molecular biology use specific methods of growing molecular biology, but more and more combine them with methods and ideas from genetics and biochemistry. There is a non-defined line between these disciplines. This is shown in the following scheme, which depicts one possible type of relationship between fields:

Biochemistry is the study of chemicals and vital processes in living organisms. Biochemists are hard to focus on the roles, functions and structures of biomolecules. The study of chemistry for biological processes and synthesis of biologically active module with examples of biochemistry.
Genetics is the study of the influence of genetic differences in organisms. This can often be removal of the normal component (for example, the gene). The study of "mutants" is organized by one or more functional components with respect to the so-called "wild type" or normal phenotype. Genetic interactions (epistasis) are often confused by simple interpretations of such "knockout" studies.
Molecular biology It is the study of the molecular basics of replication, transcription, translation and cell functioning processes. The central dogma of molecular biology, where the genetic material is transcribed in RNA and then translated into the protein, despite the extensive, still provides a good starting point for understanding the field. The picture was revised in the light of the emerging new RNA roles.

Methods of molecular biology

Molecular cloning

One of the most basic methods of molecular biology to study the protein function is molecular cloning. In this technique, DNA encoding a protein that is of interest cloned with a polymerase chain reaction (PCR), and / or restriction enzymes in plasmid (expression vector). The vector has 3 distinctive features: the start of replication, and the multiple cloning site (MCS), and the selective marker, as a rule, with resistance to antibiotics. The multiple cloning site above is promoter areas and initiation transcriptions that regulate the expression of the cloned gene. This plasmid can be inserted into either bacterial or animal cells. The administration of DNA into bacterial cells can be done by transforming with absorption of bare DNA, conjugations using intercellular contacts or by transduction using a viral vector. The introduction of DNA into eukaryotic cells, such as animal cells, with physical or chemical means, is called transfection. Several different transfection methods are available, such as transfection phosphate, electroporation, microinjection and liposomal transfection. The plasmid can be integrated into the genome, which leads to a stable transfection, or it may remain independent of the genome, called transient transformation processes.

DNA encoding proteins of interest, currently inside the cell, and proteins, can now be expressed. A variety of systems, such as inducible promoters and specific cellular signaling factors that will help express the interest of protein at high levels. Large amounts of protein can then be extracted from a bacterial or eukaryotic cell. Protein can be checked for enzymatic activity in different situations, protein can be crystallized therefore its tertiary structure can be studied, or in the pharmaceutical industry, the activity of new drugs against protein can be studied.

Polymerase chain reaction

Macromolecules Blotting and Study

Terms northern , west and oriental Blotting gets from what was originally a molecular biology joke that played on the term Sarewnet After the technique described by Edwin Southern for the Blotted DNA hybridization. Patricia Thomas, RNA developer - blotting, which was then famous as northern - Blottling , not really use this term.

SauterNibotting

Named in honor of his inventor, Biologist Edwin South, then Sarew - Blot is a method for studying for the presence of a specific DNA sequence in a DNA sample. DNA samples before or after restriction enzyme (restrictasis) digestions are separated by electrophoresis in the gel, and then transferred to the membrane using blotting using a capillary action. The membrane is then exposed to labeled DNA - probe, which has a base sequence to addition to a sequence on DNA of interest. Southern Blotting is less widely used in the scientific laboratory due to the ability of other methods, such as PCR, to detect DNA specific sequences from DNA samples. These blots are still used for some applications, however, such as the transgene measurement of the number of copies in transgenic mice or in the engineering of the gene of knockout lines of embryonic stem cells.

Northern Blottling

Northern Blot Chart

East Blotting

Clinical studies and medical treatment methods arising from molecular biology are partially covered by gene therapy. The use of molecular biology or molecular cell biology of approaches in medicine is now called molecular medicine. Molecular biology also plays an important role in the understanding of education, actions and regulations of various parts of cells, which can be used to effectively target new drugs, disease diagnosis and understand cell physiology.

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Molecular biology has grown from biochemistry in April 1953. Its appearance is connected with the names of James Watson and Francis Cry, which opened the structure of the DNA molecule. The discovery was made possible by the study of genetics, bacteria and biochemistry of viruses. Profession The molecular biologist is not widespread, but today its role in modern society is very large. A large number of diseases, including manifesting in the genetic level, requires scientists to find solutions to this problem.

Description of activity

Viruses and bacteria constantly mutate, which means that a person cease to help medicines and diseases become difficult. The task of molecular biology is to get out of this process and develop a new remedy for diseases. Scientists work according to the well-defined scheme: blocking the causes of the disease, elimination of heredity mechanisms and make it easier for the patient's condition. There are a number of centers, clinics and hospitals in the world, where molecular biologists to help patients are developing new treatments.

Labor duties

The duties of the molecular biologist include the study of the processes inside the cell (for example, changes in DNA in the development of tumors). Also, experts study the features of DNA, their influence on the whole organism and a separate cell. Such studies are carried out, for example, on the basis of PCR (polymerase chain reaction), which allows you to analyze the body on infections, hereditary diseases and determine biological relationship.

Features of career growth

Profession The molecular biologist is quite promising in its field and today claims the first places in the ranking of the medical professions of the future. By the way, the molecular biologist is not necessarily all the time to remain in this area. If there is a desire to change the generation of classes, it can retrain into laboratory equipment sales managers, start developing instruments for various studies or open your business.

The molecular biologist is a researcher in the field of medicine, the mission of which consists, no much, in the salvation of humanity from dangerous diseases. Among such diseases, for example, oncology, today has become one of the main causes of mortality in the world, only a little inferior to the leader - cardiovascular diseases. New methods for early diagnosis of cancer oncology, prevention and treatment of cancer are the priority of modern medicine. Molecular biologists in the field of oncology are developing antibodies and recombinant (genetically designed) proteins for early diagnosis or targeted delivery of drugs in the body. Specialists of this sphere use the most advanced achievements of science and technology to create new organisms and organic substances in order to further use them in research and clinical activities. Among the methods that use molecular biologists - cloning, transfection, infection, polymerase chain reaction, sequencing genes and others. One of the companies interested in molecular biologists in Russia, Praimbiomed LLC. The organization is engaged in the production of antibodies to diagnose oncological diseases. Such antibodies are mainly used to determine the type of tumor, its origin and malignant, that is, the ability to metastasis (spread to other parts of the body). Antibodies are applied to thin sections of the tissue under study, after which they are binding to cells with certain proteins - markers, which are present in tumor cells, but are absent in healthy and vice versa. Depending on the results of the study, further treatment is appointed. Among the Praimbiomed clients are not only medical, but also scientific institutions, since antibodies can be used for solving research problems. In such cases, unique antibodies can be made, capable of communicating with the protein under study, under a specific task on a special order. Another promising area of \u200b\u200bresearch of the company is targeted (target) delivery of medicines in the body. In this case, the antibodies are used as transport: with their help drugs are delivered directly to affected organs. Thus, treatment becomes more efficient and has less negative consequences for the body than, for example, chemotherapy, which affects not only cancer, but also other cells. The profession of a molecular biologist in the coming decades is expected to be increasingly popular: with an increase in the average life expectancy of a person, the number of oncological diseases will increase. Early diagnosis of tumors and innovative treatment methods with the help of substances obtained by molecular biologists will save life and improve its quality to a huge number of people.

Molecular biology, Science, which owns its task, the knowledge of the nature of life phenomena by studying biological objects and systems at the level approaching molecular, and in some cases the achievement of this limit. The ultimate goal is to find out how and to what extent characteristic manifestations of life, such as heredity, reproduce themselves similar, protein biosynthesis, excitability, growth and development, storage and transfer of information, transformation of energy, mobility, etc. , due to the structure, properties and interaction of molecules of biologically important substances, primarily two main classes of high molecular weight biopolymers - proteins and nucleic acids. Distinctive feature of M. b. - study of life phenomena on non-living facilities or those who are inherent in the most primitive manifestations of life. These are biological formations from the cellular level and below: subcellular organelles, such as insulated cell kernels, mitochondria, ribosomes, chromosome, cell membranes; Further - systems standing on the border of living and inanimate nature - viruses, including bacteriophages, and ending with molecules of the most important components of living matter - nucleic acids and proteins.

The foundation on which M. b was developed, was laid by such sciences as genetics, biochemistry, physiology of elementary processes, etc. According to the origins of its development, M. b. inextricably linked with molecular genetics, which continues to make an important part

A distinctive feature of M. b. is its three-dimensionality. Essence of M. b. Watching M. Peruz to interpret biological functions in the concepts of the molecular structure. M. b. His task to get answers to the question "How," with the essence of the role and participation of the entire structure of the molecule, and to questions "why" and "why", finding out, on the one hand, the relationship between the properties of the molecule (again, first of all, proteins and nucleic acids) and the functions carried out by it and, on the other hand, the role of such individual functions in the overall complex of life manifestations.

The most important achievements of molecular biology. This is not a complete list of these achievements: the disclosure of the structure and mechanism of the biological function of DNA, all types of RNA and Ribosomes, the disclosure of the genetic code; opening reverse transcription, i.e. DNA synthesis on the RNA matrix; study of the mechanisms of functioning of respiratory pigments; Opening of the three-dimensional structure and its functional role in the action of enzymes, the principle of matrix synthesis and mechanisms of protein biosynthesis; disclosure of the structure of viruses and the mechanisms of their replication, primary and, partially, spatial structure of antibodies; isolation of individual genes, chemical, and then biological (enzymatic) gene synthesis, including human, out of cell (in vitro); transfer of genes from one organism to another, including in human cells; rapidly going to decipher the chemical structure of the increasing number of individual proteins, mainly enzymes, as well as nucleic acids; Detecting the phenomena of "self-assembly" of certain biological objects of ever-increasing complexity, ranging from nucleic acid molecules and moving to multicomponent enzymes, viruses, ribosomes, etc.; Filming up allotic and other basic principles for regulating biological functions and processes.

Tasks of molecular biology. Along with the important tasks of M. b. (knowledge of the laws of "recognition", self-assembly and integration) the current direction of scientific search of the nearest future is the development of methods that allow decipher the structure, and then a three-dimensional, spatial organization of high molecular nucleic acids. All the most important methods, the use of which provided the emergence and successes of M. b., Were proposed and developed by physicists (ultracentrifugation, X-ray structural analysis, electron microscopy, nuclear magnetic resonance, etc.). Almost all new physical experimental approaches (for example, the use of computer, synchrotron, or brake, radiation, laser technology, etc.) open up new opportunities for in-depth study of the problems of M. b. Among the most important tasks of a practical nature, the answer to which is expected from M. b., In the first place there is a problem of the molecular foundations of malignant growth, then the warning paths, and perhaps overcoming hereditary diseases - "molecular diseases". Of great importance will be to clarify the molecular bases of biological catalysis, i.e. the actions of enzymes. Among the most important modern directions of M. b. The desire to decipher the molecular mechanisms of the torch, toxic and drugs, as well as to find out the parts of the molecular structure and the functioning of such cell structures as biological membranes involved in the regulation of the processes of penetration and vehicles of substances. More distant goals M. b. - knowledge of the nature of nervous processes, memory mechanisms, etc. One of the important emerging sections of M. b. - T. N. Genetic engineering, which places its task targeted operating in the genetic apparatus (genome) of living organisms, starting with microbes and lower (single-cell) and ending with a person (in the latter case, first of all, in order to radical treatment of hereditary diseases and correction of genetic defects).

The most important directions of MB:

- molecular genetics - study of the structural and functional organization of the genetic apparatus of cells and the mechanism for the implementation of hereditary information

- Molecular virology - study of molecular mechanisms of interaction of viruses with cells

- Molecular immunology - study of the patterns of immune responses of the body

- Molecular biology of development - a study of the emergence of varieties of cells in the course of individual development of organisms and cell specialization

The main objects of the study are viruses (including bacteriophages), cells and subcellular structures, macromolecules, multicellular organisms.