Department of Biotechnology: December 2010

BIOINFORMATICS

G.K.SANDHYA (II M.Sc )
A.RAJALAKSHMI ( III B.Sc)
R.VINOTHA (III B.Sc)

Bioinformatics is the application of statistics and computer science to the field of molecular biology. The term bioinformatics was coined by Pauline hogeweg in 1979. Common activities in bioinformatics are mapping and analyzing DNA and protein sequences, aligning different DNA and protein sequences, to compare them and creating and viewing 3D models of protein structures. Primary goal of bioinformatics is understanding of biological processes. Major research areas in this field are sequence analysis, gene annotation, computational evolutionary biology, analysis of gene expression, analysis of protein expression, analysis of mutations in cancer, prediction of protein structures, comparative genomics, protein- protein docking.

BIOINFORMATICS TOOLS
PROTEIN IDENTIFICATION AND CHARACTERISATION
MASCOT – Peptide mass finger printing
PeptIdent – allows the identification of proteins using PI, MW and peptide mass fingerprinting data.

TRANSLATION OF DNA TO PROTEIN SEQUENCE:
Translate – allows the translation of a nucleotide (DNA/RNA) to a protein sequence.
EMBOSS – Translates nucleic acid sequence to protein sequence.

SIMILARITY SEARCH AND SEQUENCE ALIGNMENT:

NCBI Blast – allows protein and nucleotide blast.
DIALIGN – for multiple alignments.

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ELISA READER

V.KOMATHI (III B.Sc)
S.REKHA(III B.Sc)

An enzyme conjugated with an antibody reacts with colorless substrate to generate a colored reaction product. A number of variations of ELISA have been developed, allowing qualitative detection or quantitative measurement of either antigen or antibody.
Enzyme linked immunosorbent assay is a sensitive laboratory method used to detect the presence of antigens (Ag) or antibodies (Ab) of interest in a wide variety of biological samples. This assay requires an immunosorbent, i.e., antigen or antibody immobilized on solid surface such as the wells of microtitre plates.
1. Indirect ELISA
2. Competitive ELISA
3. Sandwich ELISA
APPLICATIONS:
ELISA method has the advantages of simplicity and sensitivity and represents with the hormone absorbed to a matrix a situation more or less comparable to that in tissue sections.
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ANIMAL TISSUE CULTURE

S. GOMATHY( II M.Sc)
K. SRIVIDHYA( II B.Sc)

Animal tissue culture lab consists of Laminar Air Flow chamber, Co2 incubator and Inverted microscope. In this lab, Animal cells are cultured in Tissue culture flasks. There are three types of cultured cells. Primary cell cultures can be prepared by fresh cells taken from animal tissue and grown in T flasks containing appropriate mediums such as DMEM, RPMI 1640, BME, MEM etc., in sterile conditions by using LAF. The laminar air flow chamber protects the contamination of cells caused by bacteria , fungi etc., The chamber was sterilized using ethanol before starting the work and incubated in HF212UV Co2 incubator which maintains pH 6.8 to 7.6, Temperature, 5% Co2 level, stability of cells and relative humidity. Co2 incubator can be sterilized before 24 hrs and optimized for distilled water first. After that, T flask containing medium with cells can be incubated. The cells grown can be observed using inverted microscope which has high magnification, at the bottom of the large container. It differs from normal microscope by the light source and condenser on the top, above the stage pointing down, while the objectives and turret are below the stage pointing up. Then, the grown cells are trypsinized and grown in new tissue culture flask which is said to be as secondary culture. Trypsin is used to remove the adherence of cells to the culture flask.
The applications of animal tissue culture are to determine the function of a gene and cell regulations, in the preservation of highly valuable cord blood cells which are nothing but stem cells specific to an individual. It is also used in drug testing which in clinical trials the preliminary test is done in animals such as mice. The lab is also maintained in sterile conditions by frequently fumigating and using ultra violet light and following the lab rules.

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PLANT TISSUE CULTURE

S.HARI KUMAR (I Msc)
N.AMEENA BEE (I Bsc)

PLANT TISSUE CULTURE
Plant tissue culture broadly refers to the in vitro cultivation of plants, seeds and various parts of the plants. The cultivation process is invariably carried out in a nutrient culture medium under aseptic conditions. Unlike animals cells, highly mature and differentiated plant cells retain the ability of totipotency i.e, the ability of change to meristematic state and differentiate into a whole plant.
Terms used in tissue culture:
Explant:
An excised piece o f differentiated tissue or organ is regarded as an explants. The explants may be taken from any part of the plant body e.g., leaf, stem, root.
Callus:
The unorganized and undifferentiated mass of plant cells to as callus. Generally, when plant cells are cultured in a suitable medium, they divided to form callus i.e., a mass parenchymatous cells.
Dedifferentiation:
The phenomenon of mature cells reverting to meristematic state to produce callus is dedifferentiation. Dedifferentiation is possible since the non dividing quiescent cells of the explant, when grown in a suitable culture medium revert to meristematic state.
Redifferentiation:
The ability of the callus cells to differentiate into a plant organ or a whole plant is regarded as redifferentiation.
Totipotency:
The ability of an individual cell to develop into a whole plant is referred to as cellular totipotency.

Application of callus cultures:
• Nutritional requirements of plants.
• Cell and organ differentiation.
• Development of suspension and protplast cultures.
• Somaclonal variation.
• Genetic transformation.
• Production of secondary metabolites and their regulation.

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HIGH PERFORMANCE LIQUID CHROMATOGRAPHY(HPLC)

G.KARTHIK (II M.Sc)
V.VAJIRAVELU(III B.Sc)

In Isocratic HPLC the analyte is forced through a column of a stationary phase by pumping a liquid at high pressure through the column .The sample to be analysed is introduced in a small volume to the stream of mobile phase and is retarded by specific chemical or physical interaction with the stationary phase as it traverses the length of the column. The amount of retardation depends on the nature of the analyte, stationary phase and mobile phase composition. The use of pressure increases the linear velocity giving the components less time to diffuse within the column, leading to improved resolution in the resulting chromatogram.

APPLICATIONS:
1. Preparative HPLC refers to the process of isolation and purification of compounds.
2. The information that can be obtained includes identification, quantification, and resolution of a compound.
3. Chemical separations can be accomplished using HPLC by utilizing the fact that certain compounds have different migration rates given a particular column and mobile phase. Thus, the chromatographer can separate compounds from each other using HPLC; the extent or degree of separation is mostly determined by choice of stationary phase and mobile phase.

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FERMENTER

R. DEEPALAKSHMI (II M.Sc )
P. MOGANASUNDARI (III B.Sc )

Fermenter is a culture vessel used for the cultivation of microorganism for large scale production. The process which takes place in the fermenter is fermentation .The term fermentation is derived from the Latin verb fervere, to boil, thus describing the appearance of yeast on extract of fruit or malted grain. The boiling appearance is due to the production of carbon dioxide bubbles caused by the anaerobic catabolism of the sugars present in the extract. Fermentation process is of two types;

Aerobic fermentation (respiration takes place in the presence of oxygen)
Anaerobic fermentation (respiration takes place in the absence of oxygen)

Types of fermenter:

o Continuous stirred type bioreactor
o Bubble column bioreactor
o Airlift bioreactor
o Fluidized bed reactor
o Packed bed reactor
o Photo bioreactor

Parts of a fermenter:
o Agitator (impeller)
o Aeration system (Sparger)
o Baffles
o Stirrer glands and bearings

Applications of fermentation:
Produce microbial enzymes, microbial metabolites, recombinant products, microbial cells.
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LAMINAR AIR FLOW CHAMBER

S. SAKTHI(III B.Sc)

Laminar Air Flow is based on the flow of air current to create uniform velocity, along parallel lines, which helps in transforming microbial culture in aseptic conditions. When fresh air is passed in the laminar air flow it replaces the comtamintae air inside and keeps it contamination free.

APPLICATIONS:
Laminar airflow (LAF) equipment is widely used as an engineering control in aseptic processing to provide a production environment free of airborne and resulting surface contamination by microorganisms, phylogenic and drug residues, and other materials that present a risk of intravascular infection, phylogenic response, or occlusion of the peripheral vasculature. With the growth of the small- and intermediate-size generic drug manufacturing, drug repackaging, and diverse hospital pharmacy and home health care IV admixtures, compounding industries, clean space design and management has become the direct responsibility of an increasing number of middle- and line-management personnel. As such, a working knowledge of LAF theory, aseptic processing, and clean space management is integral to the conceptualization, construction, and operation of a safe and effective clean space, and an important consideration in the selection or retention of the clean space manager and operative personnel.

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HOMOGENIZER
G.PRIYANKA (ஈ B.SC)

A homogenizer is a piece of laboratory equipment used for the homogenization of various types of materials such as tissue, plants, food, soils and many others. Once the protein source has been selected, the next step is to release the desired protein from its natural cellular environment and solubilize it in aqueous solutions.

This calls for the disruption of the cell membrane without damage to the cell contents. These methods are useful for soft tissue as found in green plants and animals. Another alternative, gentle grinding is best accomplished with a glass or Teflon homogenizer. This consists of a glass tube with a close fitting piston. The cells are forced against the glass walls under the pressure of the piston, and the cell components are released in to the aqueous solutions.

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ULTRA CENTRIFUGATION
S. DEEPAK (III B.சக்)

The ultracentrifuge is a centrifuge optimized for spinning a rotor at very high speeds, capable of generating acceleration as high as 1,000,000 g (9,800 km/s²). There are two kinds of ultracentrifuges, the preparative and the analytical ultracentrifuge. Both classes of instruments find important uses in molecular biology, biochemistry and polymer science. It works based on the principle of Sedimentation. Preparative ultracentrifuges are available with a wide variety of rotors suitable for a great range of experiments. Preparative rotors are used in biology for pelleting of fine particulate fractions, such as cellular organelles (mitochondria, microscopes, and ribosomes) and viruses. They can also be used for gradient separations, in which the tubes are filled from top to bottom with an increasing concentration of a dense substance in solution. Sucrose gradients are typically used for separation of cellular organelles. Gradients of cesium salts are used for separation of nucleic acids. Different types of Rotators were used.

Centrifugation is the basic step for all techniques such as Separation of cellular
organelles, DNA isolation for electrophoresis, fingerprinting, southern blotting, etc.
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SPECTROPHOTOMETER
V.RAMYA (I M.Sc)
S.DIVYA( IIIB.Sc)

TURBIDOMETRY:
It is the process of measuring the amount of light that a solution absorbs.Light is passed through a filter creating a light of known wavelength which is then pressed through a cuvette containing a solution.A photoelectric cell collects the light which passes through the cuvette. Measurement is then given for the amount of absorbed light. It can be used in biology to find the number of cells in a solution.

The electromagnetic spectrum is composed of a continuous of waves with different properties several regions of the electromagnetic spectrum are of importance in biochemical studies including X-ray, the ultra violet, visible and then infrared and radio waves. We will concentrate on the UV and visible regions light in these regions have sufficient energy to excite the valence electrons of molecules. It shows that the propagation of light is due to an electric field component E and a magnetic field component. That is perpendicular to each other. The wavelength of light defined by equation. The distance between adjacent wave peaks.
λ = C/ γ
APPLICATIONS:
o It can be used in determining the protein.
o The compound can be identified by determining its absorption spectrum in the visible and Ultra violet region of the spectrum.
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PCR

DAYANIDHI.M.K (II M.Sc)

The purpose of a PCR (Polymerase Chain Reaction) is to make a huge number of copies of a gene. This is necessary to have enough starting template for sequencing.

The cycling reactions :
There are three major steps in a PCR, which are repeated for 30 or 40 cycles. This is done on an automated cycler, which can heat and cool the tubes with the reaction mixture in a very short time.
Denaturation( at 94°C)
Double strand melts open to single stranded DNA
All enzymatic reactions stop (for example : the extension from a previous cycle).
Annealing (at 54°C )
The primers are jiggling around, caused by the Brownian motion.
Ionic bonds are constantly formed and broken between the single stranded primer and the single stranded template.
The more stable bonds last a little bit longer (primers that fit exactly) and on that little piece of double stranded DNA (template and primer),
The polymerase can attach and starts copying the template.
Once there are a few bases built in, the ionic bond is so strong between the template and the primer, that it does not break anymore.
Extension( at 72°C )
This is the ideal working temperature for the polymerase.
The primers, where there are a few bases built in, already have a stronger ionic attraction to the template than the forces breaking these attractions.
Primers that are on positions with no exact match, get loose again (because of the higher temperature) and don't give an extension of the fragment.
The bases (complementary to the template) are coupled to the primer on the 3' side (the polymerase adds dNTP's from 5' to 3', reading the template from 3' to 5' side, bases are added complementary to the template).

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MICROSCOPE

M.INDHUMATHI (II M.Sc)
J.PRADEEP SAMUEL DASS (I B.Sc)

LIGHT MICROSCOPY:
Light from an incandescent source is aimed toward a lens beneath the stage called the condenser, through the specimen, through an objective lens, and to the eye through a second magnifying lens, the ocular or eyepiece. Some microscopes have a built-in illuminator, while others use a mirror to reflect light from an external source. The condenser is used to focus light on the specimen through an opening in the stage. After passing through the specimen, the light is displayed to the eye with an apparent field that is much larger than the area illuminated. The magnification of the image is simply the objective lens magnification (usually stamped on the lens body) times the ocular magnification.

PHASE CONTRAST MICROSCOPY:
The human eye can perceive changes in light amplitude (intensity). Unstained biological specimens, such as living cells, are essentially transparent to our eyes, but they interact with light in a fairly uniform way, by retarding (slowing) the passage of a light beam by approximately 1/4 of a wavelength ( ). By slowing a light beam this much relative to another light beam that had passed though the surrounding medium, the biological specimen alters the phase of the beams. Intensity (amplitude) is additive and light rays that are 1/2 out of phase are perceived as darkness. Zernicke realized that if he could retard the light passing through biological specimens without affecting the light passing through the surrounding medium, he could generate changes in amplitude within living cells. The phase contrast microscope was invented by Zernicke in the 1930's as a means to generate contrast in biological specimens, changing these invisible phase differences into visible amplitude differences.

FLUORESCENCE MICROSCOPY:
In certain classes of atoms and molecules, electrons absorb light, become energized, and then rapidly lose this energy in the form of heat and light emission. If the electron keeps its spin, the electron is said to enter a singlet state, and the kind of light that is emitted as the electron returns to ground state is called fluorescence. If the electron changes its spin when excited, it enters the triplet state, and the kind of light that is emitted as the electron returns to ground state is known as phosphorescence. Phosphorescence is much longer-lived than fluorescence. Both fluorescence and phosphorescence emissions are of particular wavelengths for specific excited electrons. Both types of emission are dependent on specific wavelengths of excitation light, and for both types of emission, the energy of excitation is greater than the energy of emission. Described another way, of excitation light is shorter than of emission light. In biology, we can utilize fluorescence in localization reactions, to identify particular molecules in complex mixtures or in cells. Fluorescence has the advantage of providing a very high signal-to-noise ratio, which enables us to distinguish spatial distributions of rare molecules. To utilize fluorescence, we need to label the specimen (a cell, a tissue, or a gel) with a suitable molecule (a fluorochrome) whose distribution will become evident after illumination. The fluorescence microscope is ideally suited for the detection of particular fluorochromes in cells and tissues.
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ELECTROPHORESIS

G.SUBHASHINI(I M.Sc)
J.CHITRA(III B.Sc)

Electrophoresis is a technique for separating the components of a mixture of charged molecules (proteins,DNAs or RNAs) in an electric field with a gel or other support. The movement of electrically charged molecules in an electric field often resulting in their separation.
METHODS OF ELECTROPHORESIS
 AGAROSE GEL ELECTROPHORESIS
 SDS - PAGE
 IMMUNOELECTROPHORESIS
 WESTERN BLOTTING

AGAROSE GEL ELECTROPHORESIS
This method is used to separate, identify and purify DNA fragments. The location of DNA within the gel can be determined by staining with low concentrations of the fluorescent intercalating dye Ethidium Bromide. Bands containing as little examination of the gel in UV light. If necessary this bands can be recovered from the gel and used for cloning purposes. DNA from agarose are usually run in a horizontal configuration .Agarose gels are cast by melting the agarose pouring into a mould and allowing to harden. The agarose, upon hardening, forms a matrix. When an electric field is applied across the gel, DNA, which is negatively charged at neutral pH, migrates towards the anode.
APPLICATION
 It is used to determine the molecular weight of proteins and DNA.
 It is used to determine the sequence of DNA.

SDS - PAGE
Sodium do decyl sulfate (SDS), binds to protein and the charge difference between proteins. Consequently all SDS – protein complexes migrate as anions and the mobility of the complexes is a function of molecular weight.
APPLICATION:
 SDS – PAGE is used for the determination of molecular of proteins and to analyze the purity of mixture of isozymes.
 PAGE is most versatile electrophoretic system for the analysis and separation of proteins, small RNA molecules and very small fragments of DNA.

IMMUNOELECTROPHORESIS
This techniqcombines the specificity of immunoprecipitin reaction with the separation of molecules by electrophoresis in a molecular sieving medium. The analysis is carried out usually in an agarose gel containing barbitone buffer on a microscope slide.
APPLICATION :
This technique is used to Investigate the purity of a particular antigen and to detect the presence of antigens in ,culture filterates and tissue or cell extracts.

WESTERN BLOTTING:
The technique of western blotting involves the transfer of electrophoresed protein bands from polyacrylamide gel to nylon or nitrocellulose membrane. These proteins can be detected by specific protein – ligand interaction. Antibodies are commonly used for this purpose.
APPLICATION
 It is used to identify protein.
 It is very useful to understand nucleic acid functions.

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Vacuum oven
K.GOMATHI (II.B.Sc)
N.PRATHIBA (II.B.Sc)

Under reduced air pressure, the boiling point water can be brought down to temperature well below 100.It can take place under vacuum or a controlled atmosphere can be treated through the introduction of inert gas.Vacuum evaporation is used for preserve, food and beverage products.Vacuum evaporation may also be used to concentrate the solution.
For example: evaporated milk is essentially fresh milk that has been vacuum evaporated.

Vacuum oven are specially applied for fields of medical, Agriculture, Industries and Research purpose. Vacuum oven combined with microwaving has been tried for embedding the tissue in paraffin.

APPLICATION:
 Moisture determination
 Out glassing solids
 Aging tests
 Plating
 Chemical Resistance Studies.

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Uvtransilluminator
K.Sowmiya(I B.Sc)

The passage of light through body tissues for the purpose of examining a structure interposed between the observe and the light source. A diaphonoscope is an instrument introduced into a body cavity to transilluminator tissues. Examination of an organ, cavity, or tissues by transmitted light. A valuable aid in detecting carious lesions, disclosing carious or demineralized dentin during cavity preparation, checking the finish or gingival margins of restorations and revealing cement debris or calculus subgingivally.

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pH METER
G.PRIYA (II B.SC)

pH meter is a device for pH measurements. pH meter is a precise voltmeter connected to the pH electrode - kind of ion selective electrode. Voltage produced by the pH electrode is proportional to logarithm of the H+ activity (as described by the Nernst equation). pH meter voltmeter display is scaled in such a way that the displayed result of measurement is just the pH of the solution. Commercial pH electrodes used in pH meters consist of a H+ selective membrane (which can be made just of very thin glass), and internal and external reference electrodes, usually combined in one housing .Although there are some restrictions on the use of the electrodes and the way they are treated between measurements, pH meters are in most cases the best way to check pH of the solution.
pH=log101/H+
where H+ is hydrogen ion activity

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MICROTOME

D. VASANTH III B.Sc

A microtome is a sectioning instrument that allows for the cutting of extremely thin slices of material, known as sections. It is an important device in microscopy preparation, allowing for the preparation of samples for observation under transmitted light or electron radiation. Microtome use steel, glass, or diamond blades depending upon the specimen being sliced and the desired thickness of the sections being cut. Steel blades are used to prepare sections of animal or plant tissues for light microscopy histology. It is a method for the preparation of thin sections for materials such as bones, minerals and teeth, and an alternative to electro polishing and ion milling. Microtome sections can be made thin enough to section a human hair across its breadth, with section thickness between 0.05 and 100 µm. It is used for identification of proteins, carbohydrates and lipids by histochemical methods. The methods involved are fixing, sectioning, and staining. The tissue is fixed with appropriate chemicals such as alcohols for hardening, followed by block preparation using matrix such as paraffin wax with the hardened tissue. Finally the sectioning of the blocks takes place by using microtome followed by appropriate staining. The different types of stains used are carmine, silver nitrate etc.

Proteins, carbohydrates and lipids are observed under microscope after the staining for the identification.
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DIGITAL WEIGHING MACHINE

D.Thamarai selvi (I B.Sc)

A weighing scale is a measuring instrument for determining the weight or mass of an object. An analytical balance is used to measure mass to a very high degree of precision and accuracy. The measuring pan(s) of a high precision (0.1 mg) analytical balance are inside a transparent enclosure with doors so that dust does not collect and so any air currents in the room do not affect the balance operation. A digital weighing machine wherein a mechanical change corresponding to weight of a body to be measured in taken out as an electric signal thereby to provide.

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INCUBATORS
SWARN KUMAR.B(I B.Sc)

Apparatus consisting of a box designed to maintain a constant temperature by the use of a thermostat; used for growing chicks or premature infantsIncubators promote the growth of microorganisms by maintaining a constant temperature within a narrow rangeThe optimal temperature provided in incubator ranges from 99.5-100 F (37.5-37.8ºC).
There are many types of incubators
Incubators includes various factors such as carbon dioxide atmosphere,circutating
fans, humidity controls, recording thermometers and alarm systems.Incubators are
first used to incubate poultry eggs and to incubate premature or sick infant. Now a
day’s incubators are used to grow microbial populationAt first incubators were used
by ancient China. The low cost incubators starts from 50,000 to 5,00000

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COLONY COUNTER
K.S. ASHIMA II B.SC

Colony counter is a instrument used to count colonies of bacteria or an other Microorganisms growing on other plate. To a large extent, accurate colony counting depends on the to see colonies distinctly, wheater viewed by the naked eye or by an automated instrument. Colony morphology is largely a result of the characteristics of the growth media and other environmental condition. To enhance the visibility of the colonies and enhance the counting accuracy in an even broader range of application. It is good practice to employ those procedures that form colonies that are readily discernible by their improved size,shape,distribution and contrast.
APPLICATIONS:
It is used to count the colonies of bacteria or other micro organism in the given sample
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BIOLOGICAL OXYGEN DEMAND
K.S.YAMUNA (III B.Sc)
K.Kala (III B.Sc)
The biochemical oxygen demand is a measure of the amount of oxygen used in the respiratory processes of micro organisms in oxidizing the organic matter in the sewage and for the further metabolism of cellular components synthesized from the wastes. One of the primary reasons of treating waste water prior to its being returned to the water source. Example Stream of lake.The magnitude of the BOD is related to the amount of organic material in the waste water. The strength of waste water is expressed in terms of.
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DISTILLATION UNITS

Distillation is a process in which a liquid or vapour mixture of two or more substances is separated into its component fractions of desired purity, by the application and removal of heat. It is based on the fact that the vapour of a boiling mixture will be richer in the components that have lower boiling points. Distillation columns are designed to achieve this separation efficiently.

The important aspects are:
1.Distillation is the most common separation technique.
2.It consumes enormous amounts of energy, both in terms of cooling and heating required.
3.It can contribute to more than 50% of plant operating costs.
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MAGNETIC STIRRER
D.KARTHIK(I B.Sc)
The magnetic stirrer is used in many biological labs, including microbiology labs. A magnetic stirrer is a laboratory device consisting of either a rotating magnet or stationary electromagnets creating a rotating magnetic field. This device is used to cause a stir bar immersed in a liquid to spin very quickly, agitating or mixing the liquid.A magnetic stirrer often includes a provision for heating the liquid. Stirrers are often used in laboratories, especially in the field of biology. They are preferred over gear-driven motorized stirrers because they are quieter, more efficient, and have no moving external parts to break or wear out (other than the simple bar magnet itself). Due to its small size, a stirring bar is more easily cleaned and sterilized than other stirring devices. Magnetic stirrers avoid two major problems with motorized stirrersFirstly, motorized stirrers use lubricants, which can contaminate the reaction vessel and the product. Secondly, in motorized stirrers, the sealing of the connection between the rotating shaft of the stirrer and the vessel can be problematic, especially if a closed system is needed.Magnetic stirrers also have drawbacks. For example, the limited size of the stirring bar means it can only be used for relatively small (under 4 liters) experiments. In addition, viscous liquids or thick suspensions are extremely difficult to mix using this method, although there are some stirrers with special magnets to overcome this problem.
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DEEP FREEZER
Low temperature freezers are designed for free and storing of serum. Vaccines, biological and medical specimens, clinical samples etc. at low temperature.Inner chamber is made of stainless steel. Outer body of mild steel duly powder coated.Temperature Range: AMB to – 20º C and AMB to - 40ºC.
Deep freezers are used to store medicinal specimens ,enzymes and some
biological products under low temperature.These are stored in such temperature
because some proteins are active under such conditions .It is a freezer that is
designed to keep food frozen well below freezing.
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HOT AIR OVEN

Hot air ovens are electrical devices used in sterilization. The oven uses dry heat to sterilize article.Generally, they can be operated from 50 to 300 °C (122 to 572 °F) . There is a thermostat controlling the temperature.These are digitally controlled to maintain the temperature.They do not require water and there is not much pressure build up within the oven, unlike an autoclave, making them safer to work with an hot air oven.This also makes them more suitable to be used in a laboratory

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SONICATOR
R.Dhanalakshmi (2nd biotechnology)
SONICATION:
It is physicalmethod using ultra sound waves, It is the process of converting an electrical signal into a physical vibration that can be directed toward a substance. Sonicator as vital lab equipment and are used for a number of purpose in the industry for dispersing, blending, cleaning, cell disruption.
It is most technologically advanced high indensity ultrasonic process.
Is the act of applying sound (usually ultra sound) energy to agitate particles in a sample for various purposes. In the laboratory it is usually applied using on ultra sonic bath or ultrasonic probe .In a paper machine on ultra sonic foil can distribute cellulose fibers more uniformly and strengthen the paper.

BIOLOGICAL APPLICATION
Sonication may be sufficient deactive a biological material for example sonication is often used to disrupt cell membranes and release cellular content.
This process is called sonoporation sonication is also usd to fragment molecules of DNA
Sonication is commonly used in nanotechnology.

Department of Biotechnology

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