✎✎✎ Dry Heat Sterilisation Lab Report
It is closed for a specific timeframe to sterilize the objects inside it. The second method HIPAA: Health Insurance Portability And Accountability Act Of 1996 agar slope culture where Escherichia coli are grown on Dry Heat Sterilisation Lab Report slant agar in a test tube. The solidified gel was then removed from the chamber and placed under UV light. Once the Dry Heat Sterilisation Lab Report boils the solvent vapor will travel up the distillation arm. Some examples of aerobic suspended growth techniques found in this type of Dry Heat Sterilisation Lab Report are activated sludge reactors Minarchy Advantages And Disadvantages aerated lagoons. Hyperbaric oxygen therapy to increase oxygen saturation has also been used to treat certain infections.
Dry Heat Sterilizer
After getting an amount of glass on the blowpipe it rolls on a metal surface to marver into a cone like shape. The first consists to heat a sample to liberate the water hydration, and then compare two mass weights before and after heating so gets easier to find the water percentage mass. Second step consists in chemical processes with the sample that drives to determine the percentage of the other element. Materials and chemical. Once it 's at the top it cools down and becomes less dense then this process is repeated. An example of this is in a lava lamp, once the lava on the bottom of the lava lamp heats up it becomes more dense and rises to the top where there 's less heat, then they 're it cools down and sinks to the bottom this.
Introduction: Drying is the unit operation process in which moisture presence in the moisture containing foods is being removed and so that the micro organisms like bacteria, mould and yeast cannot survive and spoil the dried food futher more. Drying process which also preserve the spoilage of the food which commonly happens by the action of enzymes it cause the foods to ripen soon while comparing to the natural occurring foods. By the same inactivation action of enzyme by the drying of the foods is not possible.
Wet material which appearance after the removal of moisture may be in the form of powder, sheets, film, flakes or granules. The drying process is separate from the evaporation of moisture from the food, where dried product is …show more content… First, second, third and fourth generation of drying method are the types of drying technique which are classified based on the historical development the drying method.
Some of the fourth generation of drying system are i microwave, ii infrared, iii radiofrequency, iv refractance window, v heat pump bed drying and vi the novel method of drying systems which come under fourth generation of drying. In the most drying methods heat is transferred into wet product which take place by the action of convection, conduction, radiation, or a combination process. The Refractance Window dryer is one among the novel method of drying in which falls under the contact, indirect, or film-drying techniques of drying food materials.
Wet product which are deposited as thin film on a conveyor belt by this method ,where the wet surface is heated by the thermal energy from hot water circulating beneath the conveyor belt. It results in the rapid drying of wet material which is placed on the moving belt ,which is in contact with the hot water. The final dried product which is then collected by scrapping action from the …show more content… The conveying belt is made of the transparent polyester film material which is food grade mylar. The wet material is floated on the surface of a heated cistern containing circulating hot water source. Figure 2: schematic representation of refractance drying system. Show More.
Read More. Department of Agriculture. The use of high-frequency ultrasound waves to disrupt cell structures is called sonication. Application of ultrasound waves causes rapid changes in pressure within the intracellular liquid; this leads to cavitation , the formation of bubbles inside the cell, which can disrupt cell structures and eventually cause the cell to lyse or collapse. Sonication is useful in the laboratory for efficiently lysing cells to release their contents for further research; outside the laboratory, sonication is used for cleaning surgical instruments, lenses, and a variety of other objects such as coins, tools, and musical instruments.
Filtration is a method of physically separating microbes from samples. Air is commonly filtered through high-efficiency particulate air HEPA filters. HEPA filters have effective pore sizes of 0. HEPA filters have a variety of applications and are used widely in clinical settings, in cars and airplanes, and even in the home. For example, they may be found in vacuum cleaners, heating and air-conditioning systems, and air purifiers. Figure Biological safety cabinets are a good example of the use of HEPA filters.
HEPA filters in biological safety cabinet s BSCs are used to remove particulates in the air either entering the cabinet air intake , leaving the cabinet air exhaust , or treating both the intake and exhaust. Use of an air-intake HEPA filter prevents environmental contaminants from entering the BSC, creating a clean area for handling biological materials. Use of an air-exhaust HEPA filter prevents laboratory pathogens from contaminating the laboratory, thus maintaining a safe work area for laboratory personnel.
Each class is designed to provide a different level of protection for laboratory personnel and the environment; BSC II and III are also designed to protect the materials or devices in the cabinet. Class I BSCs protect laboratory workers and the environment from a low to moderate risk for exposure to biological agents used in the laboratory. They are gas tight, and materials entering or exiting the cabinet must be passed through a double-door system, allowing the intervening space to be decontaminated between uses. Personnel can manipulate materials inside the Class III cabinet by using long rubber gloves sealed to the cabinet. HEPA filters are also commonly used in hospitals and surgical suites to prevent contamination and the spread of airborne microbes through ventilation systems.
HEPA filtration systems may be designed for entire buildings or for individual rooms. For example, burn units, operating rooms, or isolation units may require special HEPA-filtration systems to remove opportunistic pathogens from the environment because patients in these rooms are particularly vulnerable to infection. Filtration can also be used to remove microbes from liquid samples using membrane filtration.
Membrane filters for liquids function similarly to HEPA filters for air. Typically, membrane filters that are used to remove bacteria have an effective pore size of 0. Membrane filtration is useful for removing bacteria from various types of heat-sensitive solutions used in the laboratory, such as antibiotic solutions and vitamin solutions. Large volumes of culture media may also be filter sterilized rather than autoclaved to protect heat-sensitive components. Often when filtering small volumes, syringe filters are used, but vacuum filters are typically used for filtering larger volumes.
Membrane filters come in a variety of sizes, depending on the volume of solution being filtered. The solution is drawn through the filter by connecting the unit to a vacuum. Which of the following methods brings about cell lysis due to cavitation induced by rapid localized pressure changes? Which of the following terms is used to describe the time required to kill all of the microbes within a sample at a given temperature? Which of the following microbial control methods does not actually kill microbes or inhibit their growth but instead removes them physically from samples? Moist-heat sterilization protocols require the use of higher temperatures for longer periods of time than do dry-heat sterilization protocols do.
Skip to main content. Control of Microbial Growth. Search for:. Using Physical Methods to Control Microorganisms Learning Objectives Understand and compare various physical methods of controlling microbial growth, including heating, refrigeration, freezing, high-pressure treatment, desiccation, lyophilization, irradiation, and filtration. Think About It In an autoclave, how are temperatures above boiling achieved? Why is boiling not used as a sterilization method in a clinical setting? Think About It Does placing food in a refrigerator kill bacteria on the food?
A Streak of Bad Potluck One Monday in spring , an Ohio woman began to experience blurred, double vision; difficulty swallowing; and drooping eyelids. Think About It How does the addition of salt or sugar to food affect its water activity? Think About It What are two advantages of ionizing radiation as a sterilization method? How does the effectiveness of ionizing radiation compare with that of nonionizing radiation? This video shows how BSCs are designed and explains how they protect personnel, the environment, and the product. Think About It Would membrane filtration with a 0. Name at least two common uses of HEPA filtration in clinical or laboratory settings. Summary: Physical Methods to Control Microorganisms The tables below summarize the physical methods of control discussed in this section.
Table 1. Control Methods Using Pressure Method Conditions Mode of Action Example Uses High-pressure processing Exposure to pressures of — MPa Denatures proteins and can cause cell lysis Preservation of food Hyberbaric oxygen therapy Inhalation of pure oxygen at a pressure of 1—3 atm Inhibits metabolism and growth of anaerobic microbes Treatment of certain infections e. Control Methods Using Dessication Method Conditions Mode of Action Example Uses Simple desiccation Drying Inhibits metabolism Dried fruits, jerky Reduce water activity Addition of salt or water Inhibits metabolism and can cause lysis Salted meats and fish, honey, jams and jellies Lyophilization Rapid freezing under vacuum Inhibits metabolism Preservation of food, laboratory cultures, or reagents Table 5.
Control Methods Using Radiation Method Conditions Mode of Action Example Uses Ionizing radiation Exposure to X-rays or gamma rays Alters molecular structures, introduces double-strand breaks into DNA Sterilization of spices and heat-sensitive laboratory and medical items; used for food sterilization in Europe but not widely accepted in US Nonionizing radiation Exposure to ultraviolet light Introduces thymine dimers, leading to mutations Surface sterilization of laboratory materials, water purification Table 6. Control Methods Using Sonication Method Conditions Mode of Action Example Uses Sonication Exposure to ultrasonic waves Cavitation formation of empty space disrupts cells, lysing them Laboratory research to lyse cells; cleaning jewelry, lenses, and equipment Table 7.
Key Concepts and Summary Heat is a widely used and highly effective method for controlling microbial growth. Dry-heat sterilization protocols are used commonly in aseptic techniques in the laboratory. Pasteurization is used to kill pathogens and reduce the number of microbes that cause food spoilage. High-temperature, short-time pasteurization is commonly used to pasteurize milk that will be refrigerated; ultra-high temperature pasteurization can be used to pasteurize milk for long-term storage without refrigeration. Refrigeration slows microbial growth; freezing stops growth, killing some organisms. Laboratory and medical specimens may be frozen on dry ice or at ultra-low temperatures for storage and transport. High-pressure processing can be used to kill microbes in food.
Hyperbaric oxygen therapy to increase oxygen saturation has also been used to treat certain infections. Desiccation has long been used to preserve foods and is accelerated through the addition of salt or sugar, which decrease water activity in foods. Lyophilization combines cold exposure and desiccation for the long-term storage of foods and laboratory materials, but microbes remain and can be rehydrated. Ionizing radiation , including gamma irradiation, is an effective way to sterilize heat-sensitive and packaged materials.
Nonionizing radiation , like ultraviolet light, is unable to penetrate surfaces but is useful for surface sterilization. HEPA filtration is commonly used in hospital ventilation systems and biological safety cabinets in laboratories to prevent transmission of airborne microbes. Membrane filtration is commonly used to remove bacteria from heat-sensitive solutions. Multiple Choice Which of the following methods brings about cell lysis due to cavitation induced by rapid localized pressure changes? Sonication brings about cell lysis due to cavitation induced by rapid localized pressure changes.
Show Answer c. Thermal death time describes the time required to kill all of the microbes within a sample at a given temperature. Show Answer a. Filtration does not actually kill microbes or inhibit their growth but instead removes them physically from samples. Show Answer In an autoclave, the application of pressure to steam is increased to allow the steam to achieve temperatures above the boiling point of water. Show Answer True. Show Answer False. What is an advantage of UHT treatment? How does the addition of salt or sugar help preserve food? Which is more effective at killing microbes: autoclaving or freezing? Repeated exposure to moisture may damage the items being sterilized. The advantages and disadvantages of dry heat sterilization are already mentioned above.
Dry heat sterilization is one of the best sterilization methods. Many healthcare facilities and laboratories prefer dry heat sterilization over other methods because of the following:. Dry heat sterilization is the commonly used sterilization method in the workplace because it helps accomplish workplace goals. In the medical setting there are many instruments and items that need to be sterilized.
Dry heat method enables you to sterilize the equipment thoroughly. It does take some time but the items are cooled down easily enabling medical professionals to use them right away. Not to mention, dry heat sterilizers are way cheaper than other sterilizers. It does not affect the quality of items being sterilized and most importantly, it is not toxic to the environment. Your email address will not be published. All rights reserved. Our website services, content, and products are for informational purposes only. LaboratoryInfo does not provide medical advice, diagnosis, or treatment.
The sodium tungstate liquid is clear and colorless. Then, it was flooded with ethanol and washed immediately. Smaller disposable test packs or process challenge devices have been devised to replace the stack Democracy In Colonial America Dbq Analysis folded surgical towels for testing Dry Heat Sterilisation Lab Report efficacy of the vacuum system in a prevacuum sterilizer. Repeat a — d with three other Dry Heat Sterilisation Lab Report. Use of an air-exhaust HEPA filter prevents laboratory pathogens from contaminating the laboratory, thus maintaining a safe work area for laboratory personnel.