Common Laboratory Equipment with their Working Principles
0 likes4,545 views
The document discusses common laboratory equipment and their functions, including microscopes, autoclaves, incubators, and centrifuges, detailing their principles, uses, and methods of sterilization. It covers various concepts such as sterilization methods like moist heat and dry heat, and emphasizes the importance of these tools in scientific processes. Additionally, it explores the workings and applications of devices like pH meters and colorimeters in laboratory settings.
Common Laboratory Equipment with their Working Principles
- 1. Unit- 1 Common laboratory equipment and their functions Dr. Bimochan Poudel NVC 1188
- 2. Chapter 1. • Definition and objectives of use of lab equipments • Common terms related to lab equipments: e.g.Sterilization, autoclaving, moist heat, dry heat, refrigeration, deep freezing, distillation etc. • Principle behind the equipments • Functions of lab equipments • Identification and differention of instruments, • e.g. Microscope: (simple, compound and binocular), Autoclave, Incubator, Hot air oven, Refrigerator, Centrifuge, Distillation set, Water bath, pH Meter, Colorimeter and Weighing balances
- 3. • Sterilization : Sterilization refers to any process that removes, kills, or deactivates all forms of life and other biological agents like prions present in a specific surface, object or fluid, for example food or biological culture media • Autoclaving: Autoclaving is a sterilization method that uses high- pressure steam. The autoclaving process works by the concept that the boiling point of water (or steam) increases when it is under pressure. • Moist Heat: Moist heat sterilization describes sterilization techniques that use hot water vapor as a sterilizing agent. Moist heat sterilization using autoclave is commonly used for the sterilization of biohazardous substances, heat and moisture resistant materials such as aqueous preparation (culture media). This method is also used for the sterilization of surgical dressings and medical devices.
- 4. • Dry Heat: Dry heat sterilization of an article is one of the earliest forms of sterilization practiced. It uses hot air that is either free from water vapor or has very little of it, where this moisture plays a minimal or no role in the process of sterilization. • Refrigeration: It is the process of removing heat from an enclosed space or from a substance for the purpose of lowering its temperature
- 5. • Deep freezing : Deep-freezing is an industrial technique which involves cooling rapidly and brutally (a few minutes to an hour) food by exposing them intensely to temperatures from -30 ° C to -50 ° C, until the product core temperature reaches -18 ° C. With this process, the water contained in the cells is finely crystallized. • Distillation: Distillation is the process of separating components of a mixture based on different boiling points. Examples of uses of distillation include purification of alcohol, desalination, crude oil refining, and making liquefied gases from air
- 7. Autoclave
- 8. • The autoclave works on the principle of moist heat sterilization where steam under pressure is used to sterilize the material present inside the chamber. • The high pressure increases the boiling point of water and thus helps achieve a higher temperature for sterilization. • Similarly, the high pressure also facilitates the rapid penetration of heat into deeper parts of the material, and moisture present in the steam causes the coagulation of proteins causing an irreversible loss of function and activity of microbes. • This principle is employed in an autoclave where the water boils at 121°C at the pressure of 15 psi or 775 mm of Hg. • When this steam comes in contact on the surface, it kills the microbes by giving off latent heat.
- 9. Autoclaves are important devices to ensure the sterilization of materials containing water as they cannot be sterilized by dry heat sterilization. Besides, autoclaves are used for various other purposes. • They are used to decontaminate specific biological waste and sterilize media, instruments, and labware. • Regulated medical waste that might contain bacteria, viruses, and other biological materials are recommended to be inactivated by autoclaving before disposal. • In medical labs, autoclaves are used to sterilize medical equipment, glassware, surgical equipment, and medical wastes. • Similarly, autoclaves are used for the sterilization of culture media, autoclavable containers, plastic tubes, and pipette tips.
- 10. Incubator • An incubator is a device used to grow and maintain microbiological cultures or cell cultures. The incubator maintains optimal temperature, humidity and other conditions such as the CO2 and oxygen content of the atmosphere inside. Incubators are essential for much experimental work in cell biology, microbiology and molecular biology and are used to culture both bacterial and eukaryotic cells.
- 11. Principle and working of incubator • All incubators are based on the concept that when organisms are provided with the optimal condition of temperature, humidity, oxygen, and carbon dioxide levels, they grow and divide to form more organisms. • In an incubator, the thermostat maintains a constant temperature that can be read from the outside via the thermometer. • The temperature is maintained by utilizing the heating and no-heating cycles. • During the heating cycle, the thermostat heats the incubator, and during the no-heating period, the heating is stopped, and the incubator is cooled by radiating heat to the surrounding.
- 12. Some of the uses of incubators are given below: • Incubators are used to grow microbial culture or cell cultures. • Incubators can also be used to maintain the culture of organisms to be used later. • Some incubators are used to increase the growth rate of organisms. • These are also used for breeding of insects and hatching of eggs in zoology. • Incubators also provide a controlled condition for sample storage before they can be processed in the laboratories.
- 13. Hot Air Oven • A hot air oven is a type of dry heat sterilization. Dry heat sterilization is used on equipment that cannot be wet and on material that will not melt, catch fire, or change form when exposed to high temperatures. • Items that are sterilized in a hot air oven include: Glassware (like petri dishes, flasks, pipettes, and test tubes) Powders (like starch, zinc oxide, and sulfadiazine) Metal equipment (like scalpels, scissors, and blades) • The commonly-used temperatures and time that hot air ovens need to sterilize materials is 170 degrees Celsius for 30 minutes, 160 degrees Celsius for 60 minutes, and 150 degrees Celsius for 150 minutes.
- 15. Hot Air Oven : Working Principle • Hot air ovens use extremely high temperatures over several hours to destroy microorganisms and bacterial spores. The ovens use conduction to sterilize items by heating the outside surfaces of the item, which then absorbs the heat and moves it towards the center of the item. ( Thermal conduction is the transfer of · Heat spontaneously flows from a hotter to a colder body.)
- 16. PH Meter • In chemistry, PH is a scale used to specify the acidity or basicity of an aqueous solution. • PH meter is a device to measure the PH of the given solution. (An aqueous solution is a solution in which the solvent is water)
- 17. Working Principle of PH Meter • The overall working principle of pH sensor and pH meter depends upon the exchange of ions from sample solution to the inner solution (pH 7 buffer) of glass electrode through the glass membrane.
- 18. Use of PH Meter • PH meters are used for soil measurements in agriculture, • Use to examine, water quality for municipal water supplies, swimming pools • Use in brewing of wine or beer, manufacturing, healthcare and clinical applications such as blood chemistry • Use in laboratory diagnosis of samples
- 19. Colorimeter • A colorimeter is a device commonly used to determine the concentration of a known solute in a given solution. (Colorimetry is a scientific technique that is used to determine the concentration of colored compounds in solutions by the application of the Beer–Lambert law, which states that the concentration of a solute is proportional to the absorbance.)
- 22. Colorimeter
- 23. What is the principle of colorimeter? • The working of colorimeters is mainly based on the Beer-Lambert's Law. This law states that the light absorption when passes through a medium are directly proportional to the concentration of the medium.
- 24. Uses of Colorimeter • We use this device to test for water quality, by screening for chemicals such as chlorine, fluoride, cyanide • It also helps to determine the concentrations of plant nutrients in the soil and hemoglobin, glucose in the blood • Furthermore, it helps in the identification of substandard and duplicate drugs. • Many food industries use this device. Paints and textile manufacturers use Colorimeter. This device also checks the quality and consistency of colors in paints and fabrics, to ensure the same quality.
- 25. Refrigerator • A refrigerator (fridge) is a home appliance consisting of a thermally insulated compartment and a heat pump (mechanical, electronic or chemical) that transfers heat from its inside to its external environment so that its inside is cooled to a temperature below the room temperature.
- 26. Principle of Refrigerator • A refrigerator works on the principle of the second law of thermodynamics. This law is related to the release of heat from a body i.e. to lower the temperature of the body . The temperature of the body can be lowered by extracting or removing the heat from the material or the body . This phenomenon takes places in refrigerators as well. • The evaporator in the refrigerator is the part that makes the items in the refrigerator cold.
- 27. Uses of Refrigerator • It is used for the storage of laboratory samples for long time • It is used for storage of laboratory samples after collection and before examination. • Used to store the vaccine and for the maintenance of cold chain of the vaccines.
- 28. • Microscope: Microscope is an important device that enables us to visualize minute objects (animate and inanimate) that cannot be seen by our naked eye. • The term microscope can be split into two separate words, ‘micro’ and ‘scope’, where the term ‘micro’ means small or tiny, and ‘scope’ means to view or to observe. Therefore, a microscope can be understood as an instrument to observe tiny elements. Types of microscope A. Compound (simple) microscope (routinely used in medical laboratories) B. Phase contrast microscope C. Dark field microscope D. Fluorescence microscope
- 34. Simple microscope • A simple microscope is a magnifying glass that has a double convex lens with a short focal length. The examples of this kind of instrument include the hand lens and reading lens. When an object is kept near the lens, then its principal focus with an image is produced, which is erect and bigger than the original object. The formed image is virtual and cannot be projected on a screen like a real image. ( focal length is the distance from the center of the lens to the principal foci (or focal points) of the lens )
- 35. • A simple microscope is one that uses a single lens for magnification, such as a magnifying glass while a compound microscope uses several lenses to enhance the magnification of an object. • It uses a lens to enlarge an object through angular magnification alone, giving the viewer an erect enlarged virtual image. • The use of a single convex lens or groups of lenses is found in simple magnification devices such as the magnifying glass, loupes, and eyepieces for telescopes and microscopes. • It is actually a convex lens of small focal length, which is used for seeing the magnified images of small objects.
- 36. Following are the parts of the simple microscope with their functions: • Eyepiece: It is the lens that is used to study the samples and is placed at the top. It has a magnification of 10X to 15X. • Base: This provides support to the microscope. • Tube: This is used to connect the eyepiece to the objective lenses. • Objective lenses: These are found with the magnification of 10X, 40X and 100X and are colour coded. The lower power lenses are the shortest lens and the highest power lenses are the longest lens. • Revolving nose-piece: This is also known as the turret. It is used for holding of other objective lens and can be rotated while viewing the samples. • Diaphragm: It is used to control the amount of light that passes through the stage.
- 37. • Stage: It is the platform used for placing the slides with samples. • Stage clip: These are used to hold the slides in the proper place. • Coarse adjustment knob: It is used to focus on scanning. • Fine adjustment knob: It is used to focus on oil. • Arm: It is used to support the tube and connects to the base of the microscope. • Power switch: The main power switch used to turn on or off the microscope. • Condenser: It is used to focus the light on the sample and 400X power lenses are used.
- 38. Principle of Simple Microscope • A simple microscope works on the principle that when a tiny object is placed within its focus, a virtual, erect and magnified image of the object is formed at the least distance of distinct vision from the eye held close to the lens.
- 39. Compound microscope • The term “compound” in compound microscopes refers to the microscope having more than one lens. • Devised with a system of combination of lenses, a compound microscope consists of two optical parts, namely the objective lens and the ocular lens.
- 40. Compound microscope • Mechanical Parts of a Compound Microscope 1. Foot or base It is a U-shaped structure and supports the entire weight of the compound microscope. 2. Pillar It is a vertical projection. This stands by resting on the base and supports the stage. 3. Arm The entire microscope is handled by a strong and curved structure known as the arm. 4. Stage • The flat and rectangular plate that is connected to the arm’s lower end is called the stage. The specimen is placed on the stage for studying and examining the various features. The centre of the stage has a hole through which light can pass. 5. Inclination joint • It is a joint, where in the arm is fastened to the compound microscope’s pillar. The microscope can be tilted using the inclination joint.
- 41. 6. Clips • The upper part of the stage is connected to two clips. The slide can be held in its position with the help of the clips. 7. Diaphragm • The diaphragm is placed below the stage. It controls and adjusts the intensity of light that passes into the microscope. The diaphragm can be of two types: • Disc diaphragm • Iris diaphragm
- 42. Irish Diaphragm
- 43. Disc Diaphragm
- 44. • Optical Parts of Compound Microscope • 1. Eyepiece lens or Ocular • At the top of the body tube, a lens is planted which is known as the eyepiece. On the eyepiece, there are certain markings such as 5X, 10X, 15X, etc. These indicate the magnification power. The object’s magnified image can be observed with the help of an eyepiece. • 2. Mirror • A mirror is found attached to the pillar or the lower end of the arm. It consists of a concave mirror on one side and a plain mirror on the other side. It can be used for reflection of light rays into the microscope. • 3. Objective lenses • At the bottom of the body tube, there are two objective lenses, which are connected to the revolving nose piece. The three objective lenses are as follows: • Oil immersion objective – 100X • High power objective – 45X • Low power objective – 10X
- 45. Working Principle • It has a series of two lenses; (i) the objective lens close to the object to be observed and (ii) the ocular lens or eyepiece, through which the image is viewed by eye. Light from a light source (mirror or electric lamp) passes through a thin transparent object • The objective lens produces a magnified ‘real image’ first image of the object. This image is again magnified by the ocular lens (eyepiece) to obtain a magnified ‘virtual image’ (final image), which can be seen by eye through the eyepiece.
- 46. Characteristics Simple Microscope Compound Microscope Number of lenses One to magnify objects 3-5 to magnify objects Condenser lens Absent Present Light source Natural Illuminator Mirror type Concave reflecting One side is plain and the other side is concave Level of magnification One level only Higher-level Magnifying power Up to 300X 2,000X Adjusting Magnification No Yes Used A basic level By professional for research purpose Difference Between Simple And Compound Microscope
- 47. Uses of Microscope • It is used in laboratory to view small objects or micro-organisms. • It is used in parasitology lab for identification of parasites or parasites eggs. • It is used in hematology to observe blood components. • It is used in plant laboratory for disease diagnosis and other different purposes. • It is used to identify bacteria after grams staining and to identify blood parasites , ecto-parasites after skin scrapping test.
- 48. Binocular Microscope • A binocular microscope is any optical microscope with two eyepieces to significantly ease viewing . Most microscopes sold today are binocular microscopes though the interplay between the two lenses can differ depending on the microscope type.
- 50. Centrifuge
- 51. Types : • 1. Low speed • 2. High Speed • 3. Ultra Centrifuge
- 52. Introduction • A centrifuge is a device that uses centrifugal force to separate various components of a fluid. This is achieved by spinning the fluid at high speed within a container, thereby separating fluids of different densities or liquids from solids.
- 53. Working Principle • A centrifuge is a piece of equipment that puts an object in rotation around a fixed axis (spins it in a circle), applying a potentially strong force outward. • The centrifuge works using the sedimentation principle, where the centripetal acceleration causes denser substances and particles to move outward. • At the same time, objects that are less dense are displaced and move to the center. • In a laboratory centrifuge that uses sample tubes, the radial acceleration causes denser particles to settle to the bottom of the tube, while low- density substances rise to the top.
- 54. Centrifugal force is a force that arises from the body's inertia and appears to act on a body that is moving in a circular path which is directed away from the centre around which the body is moving
- 55. Applications / Uses • To separate two miscible substances • Purification of mammalian cells • Separating chalk powder from water • Removing fat from milk to produce skimmed milk • The clarification and stabilization of wine • Separation of urine components and blood components in forensic and research laboratories
- 56. Water Bath • A laboratory water bath is used to heat samples in the lab. Some applications include maintaining cell lines or heating flammable chemicals that might combust if exposed to open flame.
- 57. A water bath generally consists of a heating unit, a stainless steel chamber that holds the water and samples, and a control interface. Different types of water baths offer additional functionality such as a circulating water bath that keep a more even temperature or a shaking water bath that keeps the samples in motion while they are heated.
- 60. Working Principle : Water Bath • The Cu50 sensor transfer water temperature to resistance value, amplified and compared by integrated amplifier, then output the control signal and maintain water in constant temperature.
- 62. • Most human and mammalian cell lines are maintained at 36°C to 37°C for optimal growth. Insect cells are cultured at 27°C for optimal growth; they grow more slowly at lower temperatures and at temperatures between 27°C and 30°C.
- 63. Distillation Set
- 64. • Distillation is the process of separating components of a mixture based on different boiling points. • Examples of uses of distillation include purification of alcohol, desalination, crude oil refining, and making liquefied gases from air.
- 65. Working Principle • Distillation is a widely used method for separating mixtures based on differences in boiling point of the components of the mixture. • To separate a mixture of liquids, the liquid can be heated to force components, which have different boiling points, into the gas phase. The gas is then condensed back into liquid form and collected.
- 66. Uses • Distillation is used for many commercial processes, such as the production of gasoline, distilled water, xylene, alcohol, paraffin, kerosene, and many other liquids. • Gas may be liquefied and separate. For example: nitrogen, oxygen, and argon are distilled from air.
- 67. Weighing balance • A weighing balance is an instrument which is used to determine the weight or mass of an object. Available in a wide range of sizes with multiple weighing capacities they are essential tools in laboratories, commercial kitchens and pharmacies.
- 68. • Balances in medical laboratory may be: • A. Rough balances (mechanical balances) • B. Analytical balances
- 69. Rough balances: • Rough balances are several types. Some of them use sliding scale, some have a single or double pan .They are used for weighing substances, which do not call for extreme accuracy. While operating, they do not require mains electricity or battery power. • Uses/function: 1. To weigh large amounts (up to several kilo grams) 2. When a high degree of accuracy is not required it is used
- 70. Analytical balances : • Nowadays analytical and electronic balances (single pan balances that use an electro-magnetic force instead of weights) are the most popularly used balances in medical laboratories to provide a precision and accuracy for reagent and standard preparation. It requires mains electricity or battery (D.C) supplied power. These balances are used/function: 1. To weigh small quantities usually in milli gram(mg) range 2. When great accuracy is required