1. Yeast:- Yeast is an unicellular eukaryotic fungus containing a small well characterized genome. Unlike plant or animal cells, it has rather fast growth rate and itself is a non-pathogenic fungus. Most of its gene contain introns which are spliced during purification of mature mRNA. It appears that intron found in yeast contain sequences for correct splicing as they are totally absent in higher eukaryotes. Moreover, yeast can carry out post-translational modification such as removal of signal sequence from a precursor polypeptide after the secretion of cell. This reveals a major advantage of yeasts over the bacteria. Success in DNA cloning in yeast depends on uptake of foreign DNA by its spheroplast in the presence of calcium ion and polyethyleneglycol (PEG). The spheroplasts develop cell wall after the incorporation of DNA.
Biotechnology is "the integrated use of of biochemistry, microbiology And engineering science in order to achieve technological application of the capabilities of micro-organisms, cultured tissue/cells and parts thereof." Biotechnology consists of "the controlled use of biological agents, Such as, micro-organisms or cellular components, for beneficial use."
Sunday, 28 February 2021
Sunday, 31 January 2021
Properties of Good Host
A good host have the following features:-
- Should be easy transform,
- Should support the replication of recombinant DNA,
- Should be free from elements that interfere with replication of recombinant DNA,
- Lack active restriction enzyme, e.g. E.coli K12 sub strain HB 101,
- Should not have Methylases since these enzyme would methylate the replicated recombinant DNA which, as a result, would become resistant to useful restriction enzymes,
- Should be deficient in normal recombination function so that the DNA insert is not altered by recombination events. E.coli support several type of vectors, some natural, constructed, which can be grouped as follows:- 1. Plasmid 2. Bacteriophages (both natural) 3. Cosmids, 4. Phasmids 5. Shuttle vectors, 6. Artificial chromosomes 7. Phagemids,
Saturday, 30 January 2021
Types of Restriction Endonucleases
There are the following four distinct types of restriction endonucleases:-
Type 1st restriction endonucleases:- are complex endonucleases, and have recognition sequences of about 15 bp; they cleave the DNA about 1000 bp away from the 5'-end of the sequence "TCA" located within the recognition site, e.g, EcoK, EcoB, etc.
Type 2nd restriction endonucleases:- are remarkably stable and induce cleavage either, in most cases, than 350 different type 2nd endonucleases with over 100 different recognition sequences are known. They require Mg+2 ions for cleavage. The first type 2nd enzyme to be isolated was HindII in 1970. Only type 2nd restriction endonucleases are used for restriction mapping and gene cloning in view of their cleavage only at specific sites.
Type 3rd restriction endonucleases:- are intermediate between the type 1st and 2nd enzymes; they cleave DNA in the immediate vicinity of their recognition sites, e.g, EcoP1, EcoP15, HindIII, ect. Type 1st and 3rd restriction enzyme are not used in gene cloning. The type 3rd enzymes recognize asymmetric target sites, and cleave the DNA duplex on one side of the recognition sequence up to 20 bp away.
Friday, 29 January 2021
Steps in GENE CLONING
Steps in Gene Cloning:-
The entire procedure of gene cloning or recombinant DNA technology may be classified into the following five steps the convenience in description and on the basis of the chief activity performed.
- Production and isolation of the DNA fragments to cloned.
- Insertion of the isolated gene in a suitable vector to obtain recombinant DNA.
- Introduction of the recombinant DNA into a suitable organism/cell usually we used E. coli called host(transformation).
- Selection of the transformed host cells, and identification of the clone containing the desired gene/DNA fragment.
- Multiplication/expression of the introduced gene in the host.
- Where needed, transfer and expression of the gene in the another organism.
Wednesday, 27 January 2021
Autoimmune Disease
Autoimmune Disease:- The immune system normally produces antibodies against g foreign proteins but not against the native proteins of body, that is, the immune system can distinguish between "self" and "non-self", However, in rare cases, individuals begin to produce antibodies against their own antigens. These antibodies are called autoantibodies and the diseases resulting from their presence are the autoimmune diseases. Among these diseases are paroxysmal cold haemoglobinuria, myasthenia gravis and systemic lupus erythematous.
Saturday, 16 January 2021
Saturday, 2 January 2021
What is sterilization and Types of sterilization
Sterilization:-
All the materials, e.g., vessels, instruments, medium, plant material, etc., used in culture work must be freed from microbes. This is achieved by one of the following approaches:
1. Dry heat,
2. Flame sterilization,
3. Autoclaving,
4. Filter sterilization,
5. Wiping with 70% ethanol,
6. Surface sterilization,
1.Dry Heat
Glassware and Teflon plastic ware, and instruments may be sterilized by dry heat an oven at 160-180°C for 3 hours. But most workers prefer to autoclave glassware and plastic ware etc. And flame sterilize instruments like forceps, etc. More recently, glass bead sterilizers (300°C) are being employed for the sterilization of forceps, scalpels, etc. these devices use dry heat.
2.Flame Sterilization
Instrumental like forceps, scalpels, needles, etc. Are ordinary flame sterilized by dipping them in 95% alcohol followed by flaming. These instruments are repeatedly sterilized during the operation to avoid contamination. It is customary to flame the mouth of culture vessels prior to inoculation.
3.Autoclaving
Culture vessels, etc. Are generally sterilized by heating in an autoclave or a pressure cooker to 121°C at 15p.s.i. (pounds per square inch 1.06kg/cm2) for 15 to 40 minutes, The time being longer for larger medium volumes. Sterilization during autoclaving depends mainly on temperature. Certain types of plastic ware and some instruments, e.g., micropipettes, etc. Are also autoclave. Care should be taken to properly stopper all the vessels and to open the autoclave only its pressure gauge indicates zero pressure.
4. Filter Sterilization
Some growth regulators, e.g., GA3, zeatin, ABA (abscisic acid), urea, certain vitamins, and enzymes are heat labile. Such compounds are filter sterilized by passing their solution through a membrane filter of 0.45μ or lower pore size. The membrane filter is held in a suitable assembly, the assembly together with the filter is sterilized by autoclaving before use. Filter sterilized heat labile compounds are added to autoclaved and cooled media, in case of agar medium, they are added when the medium has cooled to about 40°C and is still liquefied.
Laminar flow cabinets are used to create an aseptic working space by blowing filter-sterilized air through an enclosed space. The air is first filtered through a coarse profiteer to remove large particles, it is then passed through a HEPA (high efficiency particulate air) filter, which filters out all particles larger than 0.3μm. This sterilized air blows through the cabinet at 1.8 km/hr. which is sufficient to keep the enclosed working area aseptic.
5. Wiping with 70% Ethanol
The surfaces that can not be sterilized by other techniques, e.g., platform of the laminar flow cabinet, hands of the operator, are sterilized by wiping them thoroughly with 70% ethyl alcohol is allowed to dry.
6. Surface Sterilization
All the plant materials to be used for culture are treated with an appropriate sterilizing agent to inactive the microbes present on their surface, This is called surface sterilization. Surface sterilization protocol will depend mainly on the source and the type of tissue of the explant is the excised piece of tissue or organ used for culture.
The sterilizing agent used for surface disinfection are calcium hypochlorite (9-10%), sodium hypochlorite (2%), mercuric chloride (0.1-1%), silver nitrate (1%), Bromine water (1-2%), H2O2 (10-12%) and antibiotics (4-50 mg/l). Of these, calcium or sodium hypochlorite and HgCl2 (satisfactory results) are the most commonly used. The duration of treatment varies form 15-30min. Since these agents are also toxic to plant tissues, the duration and the concentration used should be such as to cause minimum tissue death, and the rinsing after treatment should remove them as completely as possible.
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Sunday, 18 October 2020
Definition of Biotechnology
Definition of Biotechnology,
Biotechnology consists of "the controlled use of biological agents, Such as, micro-organisms or cellular components, for beneficial use." -U.S National Science Foundation,
Biotechnology is "the integrated use of of biochemistry, microbiology And engineering science in order to achieve technological application of the capabilities of micro-organisms, cultured tissue/cells and parts thereof." -European Federation of Biotechnology,
Biotechnology comprises the "controlled and deliberate application of simple biological agents living or dead, cells or cell components-in technically useful operations, either of productive manufacture or as service operation." -J.D. Bu'lock,1987,
"The application of biological organisms, systems or processes" constitutes biotechnology. -British Biotechnologist,
Biotechnology may be defined as "the use of living organisms in system or processes for the manufacture of useful products: it may involve algae, bacteria, fungi, yeast, cells, of higher plants and animals or subsystems of any of these or isolated components from living matter." -Gibbs and Greenhalgh, 1983,
Saturday, 17 October 2020
Amis Of Plant Tissue Culture
- Development of disease free plant from disease plants.
- Reducing the time it takes for the reproductive cycle to complete.
- Fixed enrichment of haploid plants.
- Creating a new plant from body hybridization and production cells.
- To develop strain resistance plants.
- Cultivation of transgenic plants.
- To produce economically important plants in large numbers in a short time.
- It does not allow the process of sexual reproduction to be necessary for crop development ensures the growth of new plants from any plant.
- Creating unusual hybrids, Such as those with protoplast conjugation with new trails develop.
Plant Tissue Culture
This can be achieved only by a combination of tissue culture and genetic engineering; none of the conventional breeding approaches can ever produce such a plant. The term tissue culture is commonly used in a very wide sense to include in vitro culture of plant cells, tissues as well as organs. But in a strict sense, tissue culture denotes the in vitro cultivation of plant cells in an unorganized mass, e.g., callus cultures. Another term, cell culture is used for in vitro culture of single or relatively small groups of plant cells, e.g., suspension cultures. But, in general, the term tissue culture is applied to both callus and suspension cultures, and cell culture is often used for callus culture as well. When organized structures like root tips, shoot tips, embryos, etc. are cultured in vitro to obtain their development as organized structures, it is called organ culture. In this book, plant tissue culture is used in its broad sense to denote aseptic in vitro culture of plant cells. tissues and organs. Thank You,
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Saturday, 12 September 2020
Types of Cancer
Cancer is not bone single disease but a complex of many disease. About two hundred distinct types of cancer have been recognized.
These can be grouped into four main types:-
1.Carcinomas
2.Sarcomas
3.Lymphomas
4. Leukemia
1. Carcinomas:- Carcinomas are tumours made up principally of epithelial cells of ectodermal of endodermal origin. The solid tumours nerve tissue and in tissues of body surfaces, or their attached glands, are examples of carcinomas. These include cervical, breast, skin, and brain carcinomas. About 85 percent of cancer are carcinomas.
2. Sarcomas:- Sarcomas are tumours made up principally of connective tissue cells, Which are of mesodermal origin. They are solid tumours growing from connective tissue. Cartilage bone and muscle. Although they account for most cancer studied in laboratory animals, they constitute only about 2 present human Cancer.
3. Lymphomas:- Lymphomas are Cancers in which there is excessive production of lymphocytes by the lymph nodes and spleen Hodgkin's disease is an example of a lymphoma. Lymphoma Constitute about 5 present of human Cancers.
4. Leukemia:- Leukemia are neoplastic growths of leucocytes (W.B.C) and are characterized by excessive production of the cells. They constitute about 4 present of human cancer.Cancer cells
RNA VIRUSES AND DNA VIRUSES NAME AND STRANDS
- Keovirus RNA(2)
- Wound Tumour Virus RNA(2)
- Rice Dwarf Virus RNA(2)
- Tobacco Mosaic Virus(TMV) RNA(1)
- Influenza Virus RNA(1)
- Polimomyelitis Virus RNA(1)
- Bacteriophage MS-2 RNA(1)
- Bacterial Virus F2 RNA(1)
- Coliphage R12 RNA(1)
- Avian Leukemia Virus RNA(1)
- Pox Viruses DNA(2)
- Coliphages T2, T4, T6, DNA(2)
- Coliphages T3, T7, DNA(2)
- Coliphages Lambda () DNA(2)
- Herpesviruses DNA(2)
- Adenoviruses DNA(2)
- Papilloma Viruses DNA(2)
- Bacteriophage Phix174 DNA(1)
- M13 DNA(1)
- Polyoma Virus SV 40 DNA(2)
Friday, 11 September 2020
Properties of A Good Vector
A good vector must have the following properties:-
- The vector should be easy to isolate and purify.
- It should be easily introduced into the host cells,transformation of the host with the vector should be easy.
- The vector should have suitable marker genes that allow easy detection and selection of the transformed host cells.
- When the object is gene transfer, it should have the ability to integrate either itself the DNA insert it carries into the genome of the host cell.
- It should be able to replicate autonomously.
- A vector should be ideally less than 10 kb in size because larger DNA molecules are broken during purification procedure.
- When expression of the DNA insert is desired, the vector should contain at least suitable control elements. e.g., promoter, operator and ribosome binding sites; several other features may be also important.
- A vector should contain unique target sites for as may restriction enzyme as possible into which the DNA insert can be integrated without disrupting an essential function.
- The cells transformed with such vector molecules that contain the DNA insert should be identifiable or selectable from those transformed by the DNA molecules only.
Wednesday, 9 September 2020
Watson And crick Model of DNA or B-DNA
Watson and Crick presented a model to elucidate the molecular structure of DNA. Which is called DNA model. For this work, Watson and Crick were awarded the Nobel prize in 1962.
Key features of DNA model are as follows:-
- Each section of DNA consists of two stands that wrap around each other form the double coil structure.
- Each DNA has two chain of polynucleotides. Which is unbranched.
- DNA has two polynucleotide chain Anti parallel. Hence, 3' of one series is near 5' of another series. Third Carbon independent of sugars at one end of polynucleotide series, Who says this 3' prime end. Fifth carbon Independent of sugar at second strand, Who says this 5' prime.
- Both polynucleotides chain are linked By hydrogen Bond.
- Nucleotides makes polynucleotides chain.(because Nucleotides are linked with Phosphodiester bond.)
- Nucleotides as step-wise arrange. The two are arranged between the series.
- Paring of Adenine to Thymine and pairing of Guanine to cytosine. Always Both are linked with Hydrogen bond.
- In the DNA of each organism or caste. Nucleotides have certain sequence.
- A=T/G≡C and A=T/G≡C ratio each organism established.
- Both polynucleotides chain of DNA chain made of a helix is 34Ã… in length.
- A total of 10 Nucleotides found in a complete helix, Distance between two Nucleotides is 3.4Ã….
- Diameter of every DNA coiled 20Ã….
- Both chain of DNA complement each other.If the sequence of bases one of its series is a A,G,A,T,G,C, then the order of bases in the second chain is T,C,T,A,C,G .
- Two DNA sequences in each DNA chain(external grooves) which are called major grooves, respectively (major grooves) and minor grooves the major grooves is wide and deep.
Tuesday, 8 September 2020
Why we want to speak English.
Thursday, 28 May 2020
All book and Notes of B.Sc Biotechnology Course.(all books Pdf.)
What is Vaccine, Vaccine designing and types of vaccine in Immunology
INTRODUCTION VACCINE - A vaccine is a biological preparation designed to provide immunity against a specific infectious diseas...
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Messenger RNA Processing:- A newly synthesized eukaryotic mRNA undergoes several modifications before it leaves the nucleus(Fig.). The firs...
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Content Introduction History Principle of PCR Stages of PCR PCR techniques PCR Requirements Steps of PCR General guidelines for Prim...