Biotechnology: Techniques, Types and Method

 Biotechnology:

    Biotechnology is a branch of biology that uses living organisms and biological processes for the benefit of humanity. It involves altering or transferring the unique characteristics of one organism into another to develop useful products and applications. Biotechnology is not a new concept. For instance, the use of bacteria in making yogurt and the grafting of plants are traditional techniques that have been practiced for centuries. 

Techniques used in biotechnology:

1. Genetic engineering
2. Tissue culture
3. Cloning
4. Fermentation

Genetic engineering:

    Genetic engineering is one of the most important techniques in biotechnology. It involves directly modifying the DNA of an organism to replace a faulty gene with a healthy one or to introduce a completely new trait. Organisms produced through this process are called genetically modified organisms (GMOs).

Methods of genetic engineering:

    The procedure generally follows these stages:

1. Identification of the gene of interest
2. Isolation and modification
3. Cloning of gene
4. Selection of molecular carrier
5. Recombinant DNA technoloy
6. Construction of recombinant DNA
7. Insertion of Recombinant DNA into the host organisms

Identification of gene of interest:

    It is the first and fundamental step in genetic engineering. We should know about the selection of desired gene with desired traits. 

Isolation and modification:

    The second step is to obtain the gene of interest. We can get gene from different sources. 

• Gene can be synthesized chemically in the laboratroy.  
• mRNA uses reverse transcriptase to make a gene. Such a gene is called a complementary gene.
• Genes can also be isolated from chromosomes. A gene can be cut from a chromosome using restriction enzymes.

After getting a gene of interest we study its traits and modify it according to our needs.

Cloning of gene:

    Cloning is technique in which we make identical copies. We need a large number of gene in order to create recombinant DNA. We use polymerase chain reaction(PCR). Polymerase enzymes can make over a billion copies in just a few hours.

 Selection of molecular carrier (vector):

    As the name suggests, it is responsible for carrying and transporting gene into the host. Specific vector used in transporting specific gene. Some common types of vector are plasmid (circular double standard DNA of E.choli), cosmids (Combination of bacteriophage DNA and plasmid), etc. 

Recombinant DNA technology:

     Combination of donor DNA and a vector is called recombinant DNA or chimaeric DNA. The laboratory method which is used to produce this type of DNA is called recombinant DNA technology. 

Construction of recombinant DNA:

• To make a recombinant DNA, firstly isolate a gene of interest.
• The donor DNA and vector is combined.
• Restriction endonuclease enzymes are used to cut and past DNA fragments.

Insertion of recombinant DNA into host cell:

    The recombinant DNA is then introduce into the host cell, this is called transformation. There are different methods to introduced DNA into the host. Some are gene gun(use for plant), viral vectors(use for animal) and chemical treatment(use for bacteria).

Tissue culture technique:

    Tissue culture is a scientific technique in which a cell, tissue or another organ is grow in an artificial medium. In 1902 a German botanist Gottlieb Haberlandt discover that plant cells are totipotent. After this discovery he invented tisue cuture technique. 

Totipotent:

    An organism in which each cell contain all genetic information is called totipotent. They can regrow in new individuals only by one cell.

There are many types of tissue culture techniques some are descibed below.

Meristem culture(micro propagation):

    Micro propagation is commercial technique for producing thousand of seedlings in shorter time. The growing points of plant where cells are capable for celldivision is called meristem. An artificial medeium is produced by adding the auxins and cytokinins.  Shoots are cut and placed into that medium, where many new shoots are formed.

Protoplast culture:

    It is a technique in which somatic embryo is produce. A naked cell witout a cell wall is called a protoplast. It is produce when enzymes are used to digest cell wall. These cells are regenerate and produces clumps. Than these clumps are maniuplated into a somatic embryo. A mature plant is produced from this embryo. It can produce a new adult plant with mutations, a process called somaclonal variation.

Cell suspension culture:

    Cell suspension is another technique for producing new adult plant with desired traits. A callus is transffered into a liquid medium. Then these clumps break off and fornm a suspension. It is used to produce chemical and drugs.

Cloning:

    Cloning is another advance technique of biotechnology. The process of making identical copies of an individual, cell or genetic material is called cloning, and the copies are called clones. There are three types of cloning. 

Reproductive cloning:

    The process of making a whole organism is called reproductive cloning. In this process a cell is transferred to ennucleated egg than embryo formed. After the formation of embryo it become a new adult organism(animal or plant)

Gene cloning:

      This process involved the cloning of gene fragment which is described in the section of genetic engeenering.

Theraputic cloning:

    This type of cloning used to make embryo for identification and treatment of diesease. A sample of gene of patient is isolate and through cloning it form an embryo. This embryo should be identical to patient cell.  

Fermentation:

    Fermentation is a process in which bacteria and fungi are used to beakdown of complex organic substances into simple substances. It an old technique used to make yogurt. Nowadays this technique is larger use on industrial scale to make yogurt, bread, alcohol and other many products. Fermentation is anaerobic process(in the absence of oxygen). There are two types of fermentation.

Alcoholic fermentation:

    In this process yeast is used for conversion of sugar into ethonol(C₂H₆OH) and carbon dioxide(CO₂).

Lactic acid fermentation:

    In this process bacteria is used for conservation of simple sugar into pyruvic acid or pyruvate(2-Oxopropanoate, 2-Oxopropanoic acid).