Burette clamp is a scientific equipment which used to hold and secure a burette on a stand, so that a burette is fixed and more convenient for the experiment. Burette clamp can be made by many materials such as cast iron. However, iron clamp with rubber knob to hold burette are to be more durable. Burette clamp comes in double, which means it can hold two burettes. Burette can be held by methods suggested below. Fix the burette on a stand, squeeze the handle, rubber knob will separate from each other. Burette will be put between the rubber knob; the rubber knob are soft and sticky due to properties of rubber, so the burettes are not to break or slip during the experiment. Retort stand Utility clamp Burette
A microplate or microtiter plate, microwell plate, multiwell, is a flat plate with multiple "wells" used as small test tubes. The microplate has become a standard tool in analytical research and clinical diagnostic testing laboratories. A common usage is in the enzyme-linked immunosorbent assay, the basis of most modern medical diagnostic testing in humans and animals. A microplate has 6, 12, 24, 48, 96, 384 or 1536 sample wells arranged in a 2:3 rectangular matrix; some microplates have been manufactured with 3456 or 9600 wells, an "array tape" product has been developed that provides a continuous strip of microplates embossed on a flexible plastic tape. Each well of a microplate holds somewhere between tens of nanolitres to several millilitres of liquid, they can be used to store dry powder or as racks to support glass tube inserts. Wells can be either circular or square. For compound storage applications, square wells with close fitting silicone cap-mats are preferred. Microplates can be stored at low temperatures for long periods, may be heated to increase the rate of solvent evaporation from their wells and can be heat-sealed with foil or clear film.
Microplates with an embedded layer of filter material were developed in the early 1980s by several companies, today, there are microplates for just about every application in life science research which involves filtration, optical detection, reaction mixing, cell culture and detection of antimicrobial activity. The enormous growth in studies of whole live cells has led to an new range of microplate products which are "tissue culture treated" for this work; the surfaces of these products are modified using an oxygen plasma discharge to make their surfaces more hydrophilic so that it becomes easier for adherent cells to grow on the surface which would otherwise be hydrophobic. A number of companies have developed robots to handle microplates; these robots may be liquid handlers which aspirate or dispense liquid samples from and to these plates, or "plate movers" which transport them between instruments, plate stackers which store microplates during these processes, plate hotels for longer term storage, plate washers for processing plates, plate thermal sealers for applying heat seals, de-sealers for removing heat seals, or microplate incubators to ensure constant temperature during testing.
Instrument companies have designed plate readers which can detect specific biological, chemical or physical events in samples stored in these plates. Microtiter are manufactured in a variety of materials; the most common is polystyrene, used for most optical detection microplates. It can be coloured white by the addition of titanium dioxide for optical absorbance or luminescence detection or black by the addition of carbon for fluorescent biological assays. Polypropylene is used for the construction of plates subject to wide changes in temperature, such as storage at -80 °C and thermal cycling, it has excellent properties for the long-term storage of novel chemical compounds. Polycarbonate is cheap and easy to mould and has been used for disposable microplates for the polymerase chain reaction method of DNA amplification. Cyclo-olefins are now being used to provide microplates which transmit ultraviolet light for use in newly developed assays. There are microplates constructed from solid pieces of glass and quartz for special applications.
The most common manufacturing process is injection molding, using materials such as polystyrene and cyclo-olefin for different temperature and chemical resistance needs. Glass is a common material, vacuum forming can be used with many other plastics such as polycarbonate. Composite microplates, filter bottom plates, solid phase extraction plates, some advanced PCR plate designs use multiple components which are moulded separately and assembled into a finished product. ELISA plates may now be assembled from twelve separate strips of eight wells, making it easier to only use a plate; the earliest microplate was created in 1951 by a Hungarian, Dr. Gyula Takátsy, who machined 6 rows of 12 "wells" in Lucite. However, common usage of the microplate began in the late 1980s when John Liner in US had introduced a molded version. By 1990 there were more than 15 companies producing a wide range of microplates with different features, it was estimated. The word "Microtiter" is a registered trademark of Cooke Engineering Company, Thermo Electron OY is the last listed owner of the trademark It is now more usual to use the generic term "microplate".
Other tradenames for microplates include Viewplate, Unifilter introduced in the early 1990s by Polyfiltronics and sold by Packard Instrument, now part of Perkin Elmer. In 1996, the Society for Biomolecular Screening known as Society for Biomolecular Sciences, began an initiative to create a standard definition of a microtiter plate. A series of standards was proposed in 2003 and published by the American National Standards Institute on behalf of the SBS; the standards govern various characteristics of a microplate including well dimensions as well as plate properties, which allows interoperability between microplates and equipment from different suppliers, is important in laboratory automation. In 2010, the Society for Biomolecular Sciences merged with the Association for Laboratory Automation to form a new organisation, the Society for Laboratory Automation and Screening. Henceforth
Laboratory water bath
A water bath is laboratory equipment made from a container filled with heated water. It is used to incubate samples in water at a constant temperature over a long period of time. All water baths have an analogue interface to allow users to set a desired temperature. Utilisations include melting of substrates or incubation of cell cultures, it is used to enable certain chemical reactions to occur at high temperature. Water bath is a preferred heat source for heating flammable chemicals instead of an open flame to prevent ignition. Different types of water baths are used depending on application. For all water baths, it can be used up to 99.9 °C. When temperature is above 100 °C, alternative methods such as oil bath, silicone bath or sand bath may be used. Use with caution, it is not recommended to use water bath with moisture pyrophoric reactions. Do not heat a bath fluid above its flash point. Water level should be monitored, filled with distilled water only; this is required to prevent salts from depositing on the heater.
Disinfectants can be added to prevent growth of organisms. Raise the temperature to 90 °C or higher to once a week for half an hour for the purpose of decontamination. Markers tend to come off in water baths. Use water resistant ones. If application involves liquids that give off fumes, it is recommended to operate water bath in fume hood or in a well ventilated area; the cover is closed to help reaching high temperatures. Set up on a steady surface away from flammable materials. Circulating the water baths are ideal for applications when temperature uniformity and consistency are critical, such as enzymatic and serologic experiments. Water is circulated throughout the bath resulting in a more uniform temperature; this type of water bath relies on convection instead of water being uniformly heated. Therefore, it is less accurate in terms of temperature control. In addition, there are add-ons that provide stirring to non-circulating water baths to create more uniform heat transfer; this type of water bath has extra control for shaking.
This shaking feature can be turned off. In microbiological practices, constant shaking allows liquid-grown cell cultures grown to mix with the air; some key benefits of shaking water bath are user-friendly operation via keypad, convenient bath drains, adjustable shaking frequencies, bright LED-display, optional lift-up bath cover, power switch integrated in keypad and warning and cut-off protection for low/high temperature. Thermal immersion circulator Heated bath Hot plate Sand bath Oil bath
An autoclave is a pressure chamber used to carry out industrial processes requiring elevated temperature and pressure different from ambient air pressure. Autoclaves are used in medical applications to perform sterilization and in the chemical industry to cure coatings and vulcanize rubber and for hydrothermal synthesis. Industrial autoclaves are used in industrial applications regarding composites. Many autoclaves are used to sterilize equipment and supplies by subjecting them to pressurized saturated steam at 121 °C for around 15–20 minutes depending on the size of the load and the contents; the autoclave was invented by Charles Chamberland in 1884, although a precursor known as the steam digester was created by Denis Papin in 1679. The name comes from Greek auto- meaning self, Latin clavis meaning key, thus a self-locking device. Sterilization autoclaves are used in microbiology, podiatry, body piercing, veterinary medicine, funerary practice and prosthetics fabrication, they vary in size and function depending on the media to be sterilized and are sometimes called retort in the chemical and food industries.
Typical loads include laboratory glassware, other equipment and waste, surgical instruments, medical waste. A notable recent and popular application of autoclaves is the pre-disposal treatment and sterilization of waste material, such as pathogenic hospital waste. Machines in this category operate under the same principles as conventional autoclaves in that they are able to neutralize infectious agents by using pressurized steam and superheated water. A new generation of waste converters is capable of achieving the same effect without a pressure vessel to sterilize culture media, rubber material, dressings, etc, it is useful for materials which cannot withstand the higher temperature of a hot air oven. Autoclaves are widely used to cure composites and in the vulcanization of rubber; the high heat and pressure that autoclaves generate help to ensure that the best possible physical properties are repeatable. The aerospace industry and sparmakers have autoclaves well over 50 feet long, some over 10 feet wide.
Other types of autoclaves are used to grow crystals under high pressures. Synthetic quartz crystals used in the electronics industry are grown in autoclaves. Packing of parachutes for specialist applications may be performed under vacuum in an autoclave, which allows the chutes to be warmed and inserted into their packs at the smallest volume, it is important to ensure that all of the trapped air is removed from the autoclave before activation, as trapped air is a poor medium for achieving sterility. Steam at 134 °C can achieve in three minutes the same sterility that hot air at 160 °C can take two hours to achieve. Methods of air removal include: Downward displacement: As steam enters the chamber, it fills the upper areas first as it is less dense than air; this process compresses the air to the bottom, forcing it out through a drain which contains a temperature sensor. Only when air evacuation is complete does the discharge stop. Flow is controlled by a steam trap or a solenoid valve, but bleed holes are sometimes used in conjunction with a solenoid valve.
As the steam and air mix, it is possible to force out the mixture from locations in the chamber other than the bottom. Steam pulsing: air dilution by using a series of steam pulses, in which the chamber is alternately pressurized and depressurized to near atmospheric pressure. Vacuum pumps: a vacuum pump sucks air or air/steam mixtures from the chamber. Superatmospheric cycles: achieved with a vacuum pump, it starts with a vacuum followed by a steam pulse followed by a vacuum followed by a steam pulse. The number of pulses depends on the particular cycle chosen. Subatmospheric cycles: similar to the superatmospheric cycles, but chamber pressure never exceeds atmospheric pressure until they pressurize up to the sterilizing temperature. A medical autoclave is a device; this means that all bacteria, viruses and spores are inactivated. However, such as those associated with Creutzfeldt–Jakob disease, some toxins released by certain bacteria, such as Cereulide, may not be destroyed by autoclaving at the typical 134 °C for three minutes or 121 °C for 15 minutes.
Although a wide range of archaea species, including Geogemma barosii, can survive and reproduce at temperatures above 121 °C, no archaea are known to be infectious or otherwise pose a health risk to humans. Autoclaves are found in many medical settings and other places that need to ensure the sterility of an object. Many procedures today employ single-use items rather than reusable items; this first happened with hypodermic needles, but today many surgical instruments are single-use rather than reusable items. Autoclaves are of particular importance in poorer countries due to the much greater amount of equipment, re-used. Providing stove-top or solar autoclaves to rural medical centers has been the subject of several proposed medical aid missions; because damp heat is used, heat-labile products cannot be sterilized this way or they will melt. Paper and other products that may be damaged by steam must be sterilized another way. In all autoclaves, items should always be separated to allow the ste
A heating mantle, or isomantle, is a piece of laboratory equipment used to apply heat to containers, as an alternative to other forms of heated bath. In contrast to other heating devices, such as hotplates or Bunsen burners, glassware containers may be placed in direct contact with the heating mantle without increasing the risk of the glassware shattering, because the heating element of a heating mantle is insulated from the container so as to prevent excessive temperature gradients. Heating mantles may have various forms. In a common arrangement, electric wires are embedded within a strip of fabric that can be wrapped around a flask; the current supplied to the device, hence the temperature achieved, is regulated by a rheostat. This type of heating mantle is quite useful for maintaining an intended temperature within a separatory funnel, for example, after the contents of a reaction have been removed from a primary heat source. Another variety of heating mantle may resemble a paint can and is constructed as a "basket" within a cylindrical canister.
The rigid metal exterior supports a "basket" made of fabric and includes heating elements within the body of the heating mantle. To heat an object, it is placed within the basket of the heating mantle. In further contrast to other methods of applying heat to a flask, such as an oil bath or water bath, using a heating mantle generates no liquid residue to drip off the flask. Heating mantles distribute heat evenly over the surface of the flask and exhibit less tendency to generate harmful hotspots. Heating element Laboratory equipment Wire gauze Double boiler
A laboratory centrifuge is a piece of laboratory equipment, driven by a motor, which spins liquid samples at high speed. There are various types of centrifuges, depending on the sample capacity. Like all other centrifuges, laboratory centrifuges work by the sedimentation principle, where the centripetal acceleration is used to separate substances of greater and lesser density. There are various types of centrifugation: Differential centrifugation used to separate certain organelles from whole cells for further analysis of specific parts of cells Isopycnic centrifugation used to isolate nucleic acids such as DNA Sucrose gradient centrifugation used to purify enveloped viruses and ribosomes, to separate cell organelles from crude cellular extractsThere are different types of laboratory centrifuges: Microcentrifuges Clinical centrifuges Multipurpose high-speed centrifuges Ultracentrifuges Because of the heat generated by air friction, the frequent necessity of maintaining samples at a given temperature, many types of laboratory centrifuges are refrigerated and temperature regulated.
There are different providers of laboratory centrifuges like Meditech, Thermo-Heraeus, Thermo-Sorvall, Beckman-Coulter, MSE, Sigma,REMI and AWEL International. Centrifuge tubes are precision-made, high-strength tubes of glass or plastic made to fit in rotor cavities, they may vary in capacity from 50 mL down to much smaller capacities used in microcentrifuges used extensively in molecular biology laboratories. Microcentrifuges accommodate disposable plastic microcentrifuge tubes with capacities from 250 μL to 2.0 mL. Glass centrifuge tubes can be used with most solvents, but tend to be more expensive, they can be cleaned like other laboratory glassware, can be sterilized by autoclaving. Small scratches from careless handling can cause failure under the strong forces imposed during a run. Glass tubes are inserted into soft rubber sleeves to cushion them during runs. Plastic centrifuge tubes tend to be less expensive and, with care, can be just as durable as glass. Water is preferred, they are more difficult to clean and are inexpensive enough to be considered disposable.
Disposable plastic "microlitre tubes" of 0.5ml to 2ml are used in microcentrifuges. They are molded from a flexible transparent plastic similar to polythene, are semi-conical in shape, with integral, hinged sealing caps. Larger samples are spun using centrifuge bottles, which range in capacity from 250 to 1000 millilitres. Although some are made of heavy glass, centrifuge bottles are made of shatterproof plastics such as polypropylene or polycarbonate. Sealing closures may be used for added leak-proof assurance; the load in a laboratory centrifuge must be balanced. This is achieved by using a combination of samples and balance tubes which all have the same weight or by using various balancing patterns without balance tubes. Small differences in mass of the load can result in a large force imbalance when the rotor is at high speed; this force imbalance strains the spindle and may result in damage to the centrifuge or personal injury. Some centrifuges have an automatic rotor imbalance detection feature that discontinues the run when an imbalance is detected.
Before starting a centrifuge, an accurate check of the rotor and lid locking mechanisms is mandatory. A spinning rotor can cause serious injury. Modern centrifuges have features that prevent accidental contact with a moving rotor as the main lid is locked during the run. For example, the new NuAire NuWind centrifuge has an automatic lid locking mechanism that locks the centrifuge lid; the chamber can be accessible only. Centrifuge rotors have tremendous kinetic energy during high speed rotation. Rotor failure, caused by mechanical stress from the high forces imparted by the motor, can occur due to manufacturing defects, routine wear and tear, or improper use and maintenance; such a failure can be catastrophic failure with larger centrifuges, results in total destruction of the centrifuge. While centrifuges have safety shielding to contain these failures, such shielding may be inadequate in older models, or the entire centrifuge unit may be propelled from its position, resulting in damage to nearby personnel and equipment.
Uncontained rotor failures have shattered laboratory windows and destroyed refrigerators and cabinetry. To reduce the risk of rotor failures, centrifuge manufactures specify operating and maintenance procedures to ensure that rotors are inspected and removed from service or derated when they are past their expected lifetime. Another potential hazard is the aerosolization of hazardous samples during centrifugation. To prevent contamination of the laboratory, rotor lids with special aerosol-tight gaskets are available; the rotor can be loaded with the samples within the rotor lid fixed on the rotor. Afterwards, the aerosol-tight system of rotor and lid is transferred to the centrifuge; the rotor can be fixed within the centrifuge without opening the lid. After the run, the entire rotor assembly, including the lid, is removed from the centri
A microscope is an instrument used to see objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small structures using such an instrument. Microscopic means invisible to the eye. There are many types of microscopes, they may be grouped in different ways. One way is to describe the way the instruments interact with a sample to create images, either by sending a beam of light or electrons to a sample in its optical path, or by scanning across, a short distance from the surface of a sample using a probe; the most common microscope is the optical microscope, which uses light to pass through a sample to produce an image. Other major types of microscopes are the fluorescence microscope, the electron microscope and the various types of scanning probe microscopes. Although objects resembling lenses date back 4000 years and there are Greek accounts of the optical properties of water-filled spheres followed by many centuries of writings on optics, the earliest known use of simple microscopes dates back to the widespread use of lenses in eyeglasses in the 13th century.
The earliest known examples of compound microscopes, which combine an objective lens near the specimen with an eyepiece to view a real image, appeared in Europe around 1620. The inventor is unknown. Several revolve around the spectacle-making centers in the Netherlands including claims it was invented in 1590 by Zacharias Janssen and/or Zacharias' father, Hans Martens, claims it was invented by their neighbor and rival spectacle maker, Hans Lippershey, claims it was invented by expatriate Cornelis Drebbel, noted to have a version in London in 1619. Galileo Galilei seems to have found after 1610 that he could close focus his telescope to view small objects and, after seeing a compound microscope built by Drebbel exhibited in Rome in 1624, built his own improved version. Giovanni Faber coined the name microscope for the compound microscope Galileo submitted to the Accademia dei Lincei in 1625; the first detailed account of the microscopic anatomy of organic tissue based on the use of a microscope did not appear until 1644, in Giambattista Odierna's L'occhio della mosca, or The Fly's Eye.
The microscope was still a novelty until the 1660s and 1670s when naturalists in Italy, the Netherlands and England began using them to study biology. Italian scientist Marcello Malpighi, called the father of histology by some historians of biology, began his analysis of biological structures with the lungs. Robert Hooke's Micrographia had a huge impact because of its impressive illustrations. A significant contribution came from Antonie van Leeuwenhoek who achieved up to 300 times magnification using a simple single lens microscope, he sandwiched a small glass ball lens between the holes in two metal plates riveted together, with an adjustable-by-screws needle attached to mount the specimen. Van Leeuwenhoek re-discovered red blood cells and spermatozoa, helped popularise the use of microscopes to view biological ultrastructure. On 9 October 1676, van Leeuwenhoek reported the discovery of micro-organisms; the performance of a light microscope depends on the quality and correct use of the condensor lens system to focus light on the specimen and the objective lens to capture the light from the specimen and form an image.
Early instruments were limited until this principle was appreciated and developed from the late 19th to early 20th century, until electric lamps were available as light sources. In 1893 August Köhler developed a key principle of sample illumination, Köhler illumination, central to achieving the theoretical limits of resolution for the light microscope; this method of sample illumination produces lighting and overcomes the limited contrast and resolution imposed by early techniques of sample illumination. Further developments in sample illumination came from the discovery of phase contrast by Frits Zernike in 1953, differential interference contrast illumination by Georges Nomarski in 1955. In the early 20th century a significant alternative to the light microscope was developed, an instrument that uses a beam of electrons rather than light to generate an image; the German physicist, Ernst Ruska, working with electrical engineer Max Knoll, developed the first prototype electron microscope in 1931, a transmission electron microscope.
The transmission electron microscope works on similar principles to an optical microscope but uses electrons in the place of light and electromagnets in the place of glass lenses. Use of electrons, instead of light, allows for much higher resolution. Development of the transmission electron microscope was followed in 1935 by the development of the scanning electron microscope by Max Knoll. Although TEMs were being used for research before WWII, became popular afterwards, the SEM was not commercially available until 1965. Transmission electron microscopes became popular following the Second World War. Ernst Ruska, working at Siemens, developed the first commercial transmission electron microscope and, in the 1950s, major scientific conferences on electron microscopy started being held. In 1965, the first commercial scanning electron microscope was developed by Profess