Name: lab cleaning methods for biosafety
Uploaded: 2023-04-30T06:59:10.000Z
Duration: 6 min 19 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Specialised Topic in Science

112.51.c.1.

112.51.c.1.C.

Decontamination for Laboratory Biosafety

1. Chemicals
<ol>
	<li>Liquid Chemicals 
	Liquid disinfectants are widely used for lab decontamination. The effectiveness of liquid disinfectants depends on a number of factors, such as the chemical nature of the disinfectant, concentration and quantity of disinfectant, contact time, and temperature. Remember, no liquid disinfectants are applicable in all situations. Make sure to select suitable disinfectants according to the detected microorganisms, using the following criteria: 
	a. Type of contaminating microorganism: Different microorganisms have different resistance towards disinfectants. For example, bacterial spores are much more chemically resistant than lipophilic viruses. 
	b. Amount of proteinaceous material present: For example, high protein materials absorb and neutralize some chemical disinfectants, such as formaldehyde and quaternary ammonium compounds. 
	c. Amount of organic material present: For example, quaternary ammonium compounds are less effective in the presence of soap and detergents. 
	d. Other important factors include the chemical nature, concentration, quantity, pH, application temperature, and toxicity of disinfectants utilized. 
	NOTE: Make sure suitable PPE is worn when working with chemical disinfectants.
	<ol>
		<li>Low-Level Disinfectants 
		A. Quaternary Ammonium (QA) Compounds: (such as benzalkonium chloride, ammonium chloride) 
		&#8226; Effective against Gram+ bacteria, Gram- bacteria, and enveloped viruses. 
		&#8226; NOT effective against non-enveloped viruses, fungi, and bacterial spores. 
		&#8226; Contain NH4+ and provide good contact with negatively charged surfaces, making them good cleaning agents. 
		&#8226; Low in toxicity but can be irritating when exposed for long durations. 
		&#8226; Commonly used in noncritical surfaces such as floors, furniture, and walls. 
		B. Phenolics: (O-phenophenoate-based compounds) 
		&#8226; Effective against bacteria, especially Gram+ bacteria and enveloped viruses. 
		&#8226; NOT effective against non-enveloped viruses and spores. 
		&#8226; Compatible with organic materials. 
		&#8226; Low in toxicity but can be irritating when exposed for long durations. 
		&#8226; Commonly used in hospital environments and laboratory surfaces.</li>
		<li>Intermediate-Level Disinfectants 
		A. Alcohols (such as ethyl alcohol and isopropyl alcohol) 
		&#8226; Effective against Gram+, Gram- bacteria, and enveloped viruses. 
		&#8226; NOT effective against spores and limited effective against non-enveloped viruses. 
		&#8226; Optimum concentration is in the range of 60-90%. Activity drops quickly when diluted below 50%. 
		&#8226; Commonly used in healthcare settings. 
		&#8226; Alcohols are flammable and quickly evaporate. 
		B. Halogen-Based Biocides: (Chlorine-based compounds and Iodophores) 
		Chlorine Compounds. 
		&#8226; Hypochlorites are the most widely used chlorine disinfectants. 
		&#8226; Effective against both enveloped and non-enveloped viruses, fungi, bacteria, and algae. 
		&#8226; NOT effective against spores. 
		&#8226; Quickly inactivated by organic matter. 
		&#8226; Degraded quickly due to the high oxidizing power. 
		C. Iodophores: An iodophor is a combination of iodine and a solubilizing agent or carrier; the resulting complex provides a sustained-release reservoir of iodine and releases small amounts of free iodine in aqueous solution. 
		&#8226; Effective against bacteria, spores, and fungi. 
		&#8226; Needs prolonged contact time. 
		&#8226; NOT effective in the presence of organic matter. 
		&#8226; Commonly used as antiseptics, for blood culture bottles, and medical equipment.</li>
		<li>High-Level Disinfectants 
		A. Oxidizers and Acids: (Hydrogen peroxide, Peracetic Acid) 
		The effect is not dependent on pH alone. For example, weak organic acids are more potent than inorganic acids despite the low dissociation constant. 
		Hydrogen peroxide: 
		&#8226; Effective against enveloped and non-enveloped viruses, vegetative bacteria, fungi, and bacterial spores. 
		&#8226; Often used as antiseptics to clean wounds and disinfect environmental surfaces. 
		&#8226; High concentration is harmful for tissues. 
		Peracetic Acid: 
		&#8226; Effective against all microorganisms with fast action. 
		&#8226; Effective in the presence of organic matter and low temperatures. 
		&#8226; Safe with no harmful decomposition products. 
		&#8226; NOT suitable for metals due to corrosion. 
		&#8226; Commonly used in automated machines to sterilize medical, surgical, and dental instruments. 
		B. Aldehydes (Formaldehyde, Glutaraldehyde) 
		Formaldehyde: 
		&#8226; Used as a disinfectant and sterilant both in gases and liquid states. 
		&#8226; Often used in a 37% percent in water solution, known as formalin. 
		&#8226; Effective against bacteria, fungi, viruses, and spores. 
		&#8226; Hazardous with an 8 hour time weighted exposure limit of 0.75 ppm. 
		&#8226; Polymerized solid form-Paraformaldehyde-is also a strong disinfectant. 
		Glutaraldehyde: 
		&#8226; 10 times more effective than formaldehyde. 
		&#8226; Effective against vegetative bacteria, spores, and viruses. 
		&#8226; Used to sterilize equipment. 
		&#8226; Effective in present of organic material. 
		&#8226; Hazardous with ceiling threshold limit 0.2 ppm and avoid skin contact.</li>
	</ol>
	</li>
	<li>Gases or Vapor 
	Vapors and gases of disinfectants include chlorine dioxide, ethylene oxide, hydrogen peroxide, peracetic acid, etc. These vapors and gases show excellent disinfection properties in closed systems such as biosafety cabinets and animal room facilities. However, well-controlled conditions of temperature, humidity, and inert gas-if flammable-must be maintained for safety. These gases or vapors are used in hospitals and commercial facilities with a need for a closed system with tight control of the temperature, humidity, and concertation.</li>
</ol>
2. Heat
<ol>
	<li>Dry Heat 
	Dry heat is used under conditions of 160-170 &#176;C for periods of 2-4 h in an appropriate oven. This method is often used for glassware or other non-porous heat conductive materials. However, it&#39;s ineffective for insulation materials or heat-labile materials.</li>
	<li>Wet Heat 
	Wet heat, also known as autoclaving, is usually under the conditions of at least 120 &#176;C for periods of 30-60 min. Autoclaving is the most convenient and dependable method to achieve effective and rapid sterilization of most forms of microbial life. Wet heat is more efficient than dry heat due to the shorter time and lower temperature required.</li>
</ol>
3. Radiation
<ol>
	<li>Ionizing Radiation 
	Ionizing radiation is not used in general laboratory sterilization due to potential issues associated with radiation safety.</li>
	<li>Non-ionizing Radiation (Ultraviolet, UV) 
	Ultraviolet radiation is typically used for decontamination in air, water, and surfaces due to its strong ability to destroy microorganisms. UV is also widely used in biological safety cabinets. The wavelength of ultraviolet radiation ranges from 250 nm to 270 nm with 265 nm as the optimum. However, UV lamp intensity drops with time, and maintenance needs to be performed after a certain time to maintain the power. Additionally, precautions need to be taken for UV light, as it can cause burns to the eyes or skin.</li>
</ol>

To avoid infection transmission and maintain biosafety in the lab, periodic decontamination in the lab is important. Three methods are available including chemical, heat, and radiation. Each method has its own strength and suitable applications. Awareness of the type of microorganism in the laboratory environment is useful for selection of a suitable decontamination method. Appropriate safety protocols should be in place during the decontamination procedure.

decontamination for laboratory biosafety

Robert M. Rioux and Zhifeng Chen, Pennsylvania State University, University Park, PA
Decontamination is essential for laboratory biosafety, as the accumulation of microbial contamination in the laboratory can lead to the transmission of disease. The degree of decontamination can be classified as either disinfection or sterilization. Disinfection aims to eliminate all pathogenic microorganisms, with the exception of bacterial spores on lab surfaces or equipment. Sterilization, on the other hand, aims to eliminate all microbial life. Different methods are available which include chemicals, heat, and radiation, and once again depend on the degree of decontamination, as well as the concentration of the contaminating microorganisms, presence of organic matter, and type of equipment or surface to be cleaned. Each method has its advantages and cautionary measures that need to be taken to avoid hazards.

Robert M. Rioux and Zhifeng Chen, Pennsylvania State University, University Park, PA
Decontamination is essential for laboratory biosafety, as the ...

Decontamination of laboratory space is essential to prevent accumulation and spreading of microbes that can lead to the transmission of diseases.Decontamination falls into two categories: disinfection and sterilization. Disinfection involves eliminating nearly all pathogenic microorganisms, with the exception of microbial spores on laboratory surfaces and equipment. Sterilization, on the other hand, is a more lethal process, eliminating all microbial life.Decontamination is carried out using a variety of methods, such as chemicals, heat, or radiation. The choice of method depends on the degree of contamination as well as the type and concentration of the contaminant.This video will illustrate the types of decontamination and the procedures for disinfection and sterilization of machines, surfaces, and equipment. Prior to establishing a decontamination procedure, the type, concentration, and location of the microorganism must be determined. Types of microorganisms include Gram-positive or -negative bacteria; viruses; fungi; bacterial spores; and algae. Once the type of microorganism is established, a suitable disinfectant should be chosen.When selecting a decontamination method the effectiveness of a disinfectant has to be considered, which is dependent on factors such as its chemical composition; the amount, concentration, contact time; and temperature.Now that we have discussed how to choose a method for decontamination, let's explore the various types used for an actual procedure. Liquid chemicals are categorized in three levels, as low-, intermediate-, and high-degree disinfectants. Regardless of which you choose, always wear appropriate personal protective equipment when working with hazardous materials.Most non-critical microorganisms require only low-level disinfectants, which are low in toxicity, but cause irritation upon long exposure times. Common low-level disinfectants are quaternary ammonium compounds, such as benzalkonium chloride and ammonium chloride, and phenolic compounds, such as o-phenylphenol and chloroxylenol.For the decontamination of more resistant microorganisms, alcohol-based chemicals are used in areas ranging from healthcare to laboratories.Additionally, halogen-based compounds, such as hypochlorites and iodophors are often applied as antiseptics and disinfectants of medical equipment. However these agents have prolonged contact times and their effectiveness is decreased in the presence of organic matter.High level disinfectants, which can be classified as oxidizers, acids, and aldehydes are used if decontamination of all microorganisms is required.Oxidizers such as hydrogen peroxide are fast-acting and often used as antiseptics for wound cleaning and to disinfect environmental surfaces like benchtops. But be careful, as exposure to high concentrations of hydrogen peroxide can be harmful to tissue and airways.Peracetic acid is generally used to disinfect automated machines and to sterilize medical, surgical, and dental instruments. The advantage of peracetic acid and other oxidizers is a short contact time; however, the use of material to be disinfected can be limited, due to corrosion of metals in acids, for example.Aldehydes on the other hand, such as formaldehyde or gluteraldehyde, are non-corrosive, but are still hazardous. These chemicals are used to sterilize various types of equipment, but suffer from prolonged contact time. In addition to liquid chemicals, gaseous chemicals may also be used for decontamination purposes. Gases such as chlorine dioxide and ethylene oxide, as well as vaporized hydrogen peroxide and peracetic acid are frequently used to rid closed equipment, such as biosafety cabinets, of bacteria, viruses, and spores. In addition to chemicals, heat is a common physical agent for the decontamination of pathogens.There are two forms of heat. "Dry" heat is used under conditions of 160 to 170 degrees Celsius for 2 to 4 hours to disinfect glassware, but it is not suitable for heat-labile materials. On the other hand, "Wet" heat, also known as autoclaving, is used by heating samples and equipment to only 120 degrees Celsius for 30 to 60 minutes under high pressure.Besides heat, ultraviolet radiation in the wavelength range of 250 to 270 nanometers is often used for decontamination. This method is effective against bacteria and viruses, but not against spores, and is used to decontaminate air, water, and surfaces such as in biological safety cabinets. Furthermore UV light in this range can cause burns of skin and eyes, thus proper PPE should be worn. You've just watched JoVE's introduction to Decontamination for Laboratory Safety. You should now understand the various types of microbial contaminants, how to choose a suitable method, and the types of disinfection and sterilization available. Thanks for watching!

Education

JoVE Science Education

Basic Biology

Lab Safety

lab cleaning methods for biosafety

Laboratory cleaning methods are a key part of biosafety because microbial contamination can build up and spread disease. Decontamination is used to reduce that risk on lab surfaces and equipment. The level of cleaning depends on how much contamination is present and what kind of item needs treatment.

Decontamination can be grouped into disinfection and sterilization. Disinfection removes pathogenic microorganisms, but it does not remove bacterial spores on lab surfaces or equipment. Sterilization is the more complete step, because it aims to eliminate all microbial life.

Several methods can be used, including chemicals, heat, and radiation. The best choice depends on the level of decontamination needed, the concentration of the microorganisms, the presence of organic matter, and the type of surface or equipment being cleaned. Each method has benefits, and each also requires caution to avoid hazards.

Lab Cleaning Methods for Biosafety

proper personal protective equipment

Choosing the Right Lab PPE

Choosing the right lab PPE is a key part of working safely in a laboratory. PPE, or personal protective equipment, helps reduce risk when hazards are present. Laboratory hazards can be many and varied. The right choice of PPE helps make the lab a safe place to work. Students should match their protective gear to the tasks and conditions in the lab. This topic focuses on selecting proper protection for the situation at hand. Wearing the correct PPE supports safer lab work and helps limit...

emergency eyewash and shower stations

Laboratory Chemical Spill Response Stations

Laboratory chemical spill response stations help protect people who are exposed to injurious or corrosive substances. In workplaces and school labs, OSHA requires emergency eyewash and shower stations to be easy to reach when these hazards are present. These stations are used after an accident that spills a harmful chemical on the body or splashes it into the eyes. The eyewash station helps rinse the eyes, while the shower station is used for chemicals on the skin or clothing. They are meant...

electrical safety

Preventing Lab Electric Shock and Fires

Electrical hazards are a common lab safety concern. Most laboratory equipment uses electricity to work, so students and lab staff must stay alert around cords, plugs, and powered devices. Improper use of electrical equipment can cause electric shock. In serious cases, this can lead to injury or death. Electrical sparks are also dangerous in the lab. They can start a fire or trigger an explosion. This risk matters because many flammable chemicals may be stored near powered instruments. Knowing...

working with centrifuges

Centrifuge Safety and Sample Separation

Centrifuges are used to separate heterogeneous mixtures by spinning particles in a fluid at high speed. The motion creates a force away from the axis of rotation. Heavier particles move faster toward the bottom of the sample holder, and the rate depends on particle size and density. This process is called centrifugation, and it speeds up sedimentation, which is the settling of particles out of a liquid. Gravity can separate some mixtures on its own, but that can take a long time.

working with hot and cold sources

Safe Use of Lab Heat and Cold Sources

Safe use of lab heat and cold sources is an important part of laboratory work. Extreme temperatures are common in many lab tasks. They can involve both high heat and very low temperatures. Bunsen burners and hot plates are widely used in research labs and industry. A Bunsen burner is a gas burner that gives a direct flame. A hot plate is an electric device that warms containers without an open flame. Because these tools reach high temperatures, users need to follow safe handling procedures. <br...

guidelines in case of a laboratory emergency

guidelines-in-case-of-a-laboratory-emergency

Lab Spill and Accident Response Basics

Lab spill and accident response basics help students stay safe during common laboratory emergencies. The most common lab emergencies include chemical spills, fire or explosion, electric shock, and personnel injuries. Many accidents happen because of poor planning or lack of attention, so prevention is always the first step. Good lab safety starts before an emergency happens. Students should wear proper personal protective equipment, or PPE, in the laboratory. Regular lab inspection and...

chemical storage: categories, hazards and compatibilities

chemical-storage-categories-hazards-and-compatibilities

Safe Chemical Labels and Storage Basics

Safe chemical storage and labeling help prevent dangerous reactions in school and research labs. Chemicals can vary widely in their properties and reactivity, so they must be managed, stored, and labeled correctly as part of an Environmental, Health and Safety (EHS) program. If chemicals are not handled properly, they can create harmful or even destructive results. These risks include toxic fume production, fire, explosion, human fatality, property damage, and environmental hazards. Proper...

safe handling of mineral acids

Mineral Acids in the Lab

Mineral acids are common chemicals in research laboratories, and they must be handled with care. These acids, also called inorganic acids, are water-soluble acids formed from inorganic minerals by chemical reaction. Their corrosive nature makes them a major safety risk in the lab. Examples of mineral acids include boric acid, chromic acid, hydrochloric acid, hydrofluoric acid, nitric acid, perchloric acid, phosphoric acid, and sulfuric acid. These acids are important reagents in research, and...

handling chemical spills

Chemical Spill Safety in the Lab

Chemical spill safety in the lab is essential whenever hazardous chemicals are used. Spills can happen at any time during laboratory work. Even a small spill can become dangerous if people are not prepared to respond quickly and correctly. Preparing for a chemical spill helps protect public health and the environment. Lab teams need to know how to respond to accidental releases of hazardous chemicals before an emergency happens. Safe cleanup also depends on proper disposal of the spilled...

proper use of autoclaves

Autoclaving Lab Materials Safely

Autoclaving lab materials safely is an important part of decontamination in the laboratory. This method is commonly used for items that have contacted biological samples, especially those that may contain microorganisms. An autoclave cleans materials with pressurized steam at a high temperature. The steam and heat work together to kill microorganisms on the loaded items. For this reason, effective autoclaving depends on good steam flow and strong heat transfer. Packaging matters because it...

fume hoods and laminar flow cabinets

Airflow Controls for Safer Lab Workspaces

Fume hoods and laminar flow cabinets are airflow controls used in laboratories. They both rely on a constant stream of air to protect the lab environment and the people in it. These systems work in similar ways, but they serve different purposes. A fume hood is a ventilation system that helps reduce exposure to hazardous vapors, fumes, and particles. Air is drawn into the hood opening, which helps keep harmful substances inside the workspace. The air is then pulled out through the exhaust. A...

handling air- and water-sensitive chemicals using a schlenk line

handling-air-and-water-sensitive-chemicals-using-a-schlenk-line

Schlenk Line Setup for Inert Atmospheres

A Schlenk line helps chemists work with air- and water-sensitive chemicals. It provides an air-free way to handle reagents that can react with oxygen or moisture. This makes it useful in a chemical laboratory when careful control of the atmosphere is needed. The glass apparatus is commonly used because it can create an inert gas environment or a vacuum. Inert gases such as nitrogen and argon can be used to protect the reaction. The same setup can also expose glassware to vacuum when needed. A...

proper operation of vacuum based equipment

proper-operation-of-vacuum-based-equipment

Vacuum Pumps for Laboratory Procedures

Vacuum pumps are used in many laboratory procedures that need low pressure. They help create vacuum conditions for experiments and equipment that must run below normal atmospheric pressure. In the lab, vacuum pumps are the most common way to achieve this low-pressure environment. They can also support rapid changes in the atmosphere inside a reactor or flask. This is done by evacuating the vessel and then backfilling it with another gas.

operating the glovebox

Glovebox Atmosphere and Sample Transfer

A glovebox is an enclosed workspace that keeps an inert atmosphere inside. Scientists use built-in gloves to handle chemicals or equipment without exposing the inside of the box to outside air. The box uses positive pressure to help make up for small passive leaks. Objects can be moved in and out through an antechamber, which works like an airlock between the glovebox and the outside atmosphere. Some gloveboxes have more than one pair of gloves. The number of glove ports depends on the size...

operation of high-pressure reactor vessels

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Safe Use of Pressure Vessels in Chemistry

High-pressure reactor vessels are used in synthetic chemistry to handle gases safely during reactions. They help chemists carry out gas-based processes such as hydrogenation, oxidation, and amination. These reactions often use hydrogen, oxygen, or ammonia, which are important reagents in the lab. These gases usually dissolve poorly in standard reaction mixtures. Because of that, high pressure is needed to make the reaction proceed at a useful rate. The vessel creates a sealed space that keeps...

Laboratory cleaning methods are a key part of biosafety because microbial contamination can build up and spread disease. Decontamination is used to reduce that risk on lab surfaces and equipment. The level of cleaning depends on how much contamination is present and what kind of item needs treatment. Decontamination can be grouped into disinfection and sterilization. Disinfection removes pathogenic microorganisms, but it does not remove bacterial spores on lab surfaces or equipment.

proper waste disposal

Lab Waste Management and Safety

Lab waste management and safety are essential parts of any laboratory activity. Waste generated during work must be handled correctly from the moment it is created until it reaches its final offsite disposal facility. Poor waste disposal can seriously harm public health and the environment. A waste management system should be planned before any lab work begins. This system guides how waste is collected, stored, and prepared for removal. For hazardous waste, special rules apply because its...

lab safety

This collection provides safety guidelines to be followed when working with hazardous materials and equipment. It covers universal topics such as PPE, electrical safety, and general emergency guidelines, as well as some specific safety procedures for chemistry and biology laboratories.

Learn how decontamination supports lab biosafety through disinfection and sterilization using chemicals, heat, or radiation on lab surfaces and equipment.

Lab Cleaning Methods for Biosafety | JoVE K12

Biology

BIO.1

BIO.1.C

Chemistry and Physics

IPC.1

IPC.1.C

Robert Rioux

Overview

Choosing a Decontamination Method

Disinfecting with Liquid Chemicals

Disinfecting with Gaseous Chemicals

Decontamination with Heat or Radiation

Summary

The Scientific Method

The scientific method is a detailed, empirical problem-solving process used by biologists and other scientists. This iterative approach involves ...

Inductive Reasoning

Inductive reasoning is a form of logical thinking that uses related observations to arrive at a general conclusion. It is uncertain and operates in ...

Deductive Reasoning

Deductive reasoning, or deduction, is the type of logic used in hypothesis-based science. In deductive reasoning, the pattern of thinking moves in the ...

Correlation and Causation

Correlation and CausationStatistical tests can calculate whether there is a relationship, or correlation, between independent and dependent variables. A ...

Ask questions and define problems related to specialized topics of study based on observations or information from text, phenomena, models, or investigations;

112.51.c.1.A.

Scientific Method

The scientific method is used to solve problems and explain phenomena. The development of the scientific method coincided with changes in philosophy ...

Demonstrating the Scientific Method with Tree Branches
ExpandObtain branches containing a few dozen typical leaves from five different local tree species. ...

Observation and Background Research
ExpandNOTE: The first two steps in the scientific process involve studying and observing natural phenomena of ...

Problem-Solving

A problem-solving strategy is a plan of action used to find a solution. It involves trial and error, algorithms, heuristics, and insights. Effective ...

Problem Definition

Problem definition is the initial and the most essential step in research.
The researcher identifies and explains the specific issue or gap to be ...

Apply science practices related to specialized topics of study to plan and conduct investigations or use engineering practices to design solutions to problems;

112.51.c.1.B.

Proper Personal Protective Equipment

Robert M. Rioux &#38; William A Elliott, Pennsylvania State University, University Park, PA
Hazards are many and varied in the laboratory, but the right ...

Emergency Eyewash and Shower Stations

Robert M. Rioux, Pennsylvania State University, University Park, PA
The Occupational Safety and Health Administration (OSHA) mandates that an emergency ...

Electrical Safety

Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Among the many hazards present in the laboratory, electrical ...

Working with Centrifuges

Source: Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Earth's gravitational force is capable of separating ...

Working with Hot and Cold Sources

Source: Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Working with extreme temperatures, both high and low, ...

Guidelines in Case of a Laboratory Emergency

Robert M. Rioux &amp; Zhifeng Chen, Pennsylvania State University, University Park, PA
The most common laboratory emergencies include chemical spills, ...

Chemical Storage: Categories, Hazards And Compatibilities

Source: Robert M. Rioux &amp; Taslima A. Zaman, Pennsylvania State University, University Park, PA
While the use of various chemicals in experimental ...

Safe Handling of Mineral Acids

Source: Robert M. Rioux &#38; Taslima A. Zaman, Pennsylvania State University, University Park, PA
A mineral acid (or inorganic acid) is defined as a ...

Handling Chemical Spills

Source: Robert M. Rioux &#38; Taslima Zaman, Pennsylvania State University, University Park, PA
Since chemicals are commonly used for laboratory research ...

Proper Use of Autoclaves

Robert M. Rioux &amp; Zhifeng Chen, Pennsylvania State University, University Park, PA
Autoclaving is one of the most commonly used methods in the ...

Fume Hoods and Laminar Flow Cabinets

Robert M. Rioux &amp; William A. Elliott, Pennsylvania State University, University Park, PA
Fume hoods and laminar flow cabinets are engineering controls ...

Proper Waste Disposal

Robert M. Rioux and Taslima A. Zaman, Pennsylvania State University, Pennsylvania, PA

Users are responsible for the proper disposal of the waste ...

Use appropriate safety equipment and practices during laboratory, classroom, and field investigations as outlined in Texas Education Agency-approved safety standards;

Common Lab Glassware and Uses

Source: Laboratory of Dr. Neal Abrams &#8212; SUNY College of Environmental Science and Forestry
Glassware is a regular appearance in the professional ...

Lab Techniques

Measurement Accuracy
The ability to repeat an experiment and get the same results, or reproducibility, is essential in scientific research. However, ...

Source: Smaa Koraym at Johns Hopkins University, MD, USA

	Preparation of LaboratoryExpand
	Here we show the laboratory preparation for 10 students ...

Source: Smaa Koraym at Johns Hopkins University, MD, USA

	Determining the Density of an EggExpand
	Density is a measure of how compact a substance or ...

Proper Lab Notebook Keeping

Organic Lab Notebook Keeping
Record keeping is a vital skill in science and organic chemistry labs. Without proper notes, descriptions, quantities, or ...

Source: Lara Al Hariri at the University of Massachusetts Amherst, MA, USA

	Preparation of the LaboratoryExpand
	Here, we show the laboratory preparation ...

Source: Lara Al Hariri and Ahmed Basabrain at the University of Massachusetts Amherst, MA, USA

	Nitration of Methyl BenzoateExpand
	From this lab onward, ...

Use tools appropriate to the specialized topic of study;

112.51.c.1.D.

SI Units: 2019 Redefinition

Measurement is integral to analytical chemistry. Each record comprises a number &#8211; denoting the magnitude&#160; &#8211; and the unit &#8211; a ...

International System of Units

The International System of Units, known as the SI system, is a universally accepted measurement system recognized and used worldwide. The SI system is ...

Measurement: Standard Units

Every measurement provides three kinds of information: the size or magnitude of the measurement (a number), a standard of comparison for the measurement ...

Measurement: Derived Units

The International System of Units or SI system, by international agreement, has fixed measurement units for seven fundamental properties: length, mass, ...

Collect quantitative data using the International System of Units (SI) or qualitative data as evidence as appropriate to the specialized topic of study;

112.51.c.1.E.

Review and Preview

Data are individual items of information obtained from a population or sample. Data may be classified as qualitative (categorical), quantitative ...

What is a Frequency Distribution

A frequency is the number of times a value of the data occurs. The sum of all the frequency values represents the total number of students included in the ...

Cumulative Frequency Distribution

A cumulative frequency distribution is another type of frequency distribution. Instead of reporting how many data values fall in some classes, it reports ...

Ogive Graph

An ogive graph is sometimes called a cumulative frequency polygon. It is one type of frequency polygon that shows cumulative frequency. In other words, ...

Histogram

The histogram is a graphical representation in the x-y form of data distribution in a data set. The horizontal x-axis is labeled with what the data ...

Relative Frequency Histogram

The relative frequency depicts the proportion of data points that have each value. The frequency tells the number of data points that have each value. ...

Scatter Plot

The most common and easiest way to display the relationship between two variables, x and y, is a scatter plot. A scatter plot shows the direction of a ...

Time-Series Graph

A time-series graph is a line graph with repeated measurements taken at successive intervals of time. It is also called a time series chart. To construct ...

Bar Graph

A bar graph is also called a bar chart and consists of bars that are separated from each other. It either uses horizontal or vertical bars to show ...

Multiple Bar Graph

As the name suggests, a multiple bar graph is the same as a bar graph but has multiple bars to depict relationships between different data values. One can ...

Pareto Chart

A Pareto chart is a bar graph or a combination of both line and bar graphs. The bar lengths represent the individual values or the frequency, while the ...

Pie Chart

A pie chart (or a pie graph) is a circular graphical chart or a pictorial representation of categorical data. It is divided into slices of pie each ...

Organize quantitative or qualitative data using representations appropriate to the specialized topic of study such as scatter plots, line graphs, bar graphs, charts, data tables, diagrams, scientific drawings, and student-prepared models;

112.51.c.1.F.

Modeling and Similitude

A scaled model of a dam is tested in a controlled environment to observe how it will manage water flow, turbulence, and pressure.
This setup predicts the ...

Typical Model Studies

Typical model studies analyze scaled-down systems to predict fluid behavior, focusing on interactions with free surfaces and flow around immersed bodies.
...

design-example-creating-a-hydraulic-model-of-a-dam-spillway

Design Example: Creating a Hydraulic Model of a Dam Spillway

A hydraulic model of a dam spillway is often created by scaling down the design, typically to a 1:15 ratio, to replicate key flow characteristics such as ...

Models, Theories, and Laws

Scientists frequently use models to help them comprehend a specific collection of phenomena. In physics, a model is a condensed version of a physical ...

/files/media/science-education/science-education-thumbs/14686.jpg

Concepts and Prototypes

The human nervous system translates sensory stimuli into neural impulses, which the brain processes into information as thoughts and memories, forming ...

Molecular Models

Physical models representing molecular architectures of chemical compounds play essential roles in understanding chemistry. The use of molecular models ...

Develop and use models to represent phenomena, systems, processes, or solutions to problems as appropriate to the specialized topic of study; and

112.51.c.1.G.

Scientific Laws and Theories

Scientific Laws

In science, a law is defined as a concise, verbal or mathematical, statement that summarizes a vast number of experimental observations. ...

Distinguish among scientific hypotheses, theories, and laws as appropriate to the specialized topic of study.

112.51.c.1.H.

Scientific and engineering practices. The student, for at least 40% of instructional time, asks questions, identifies problems, and plans and safely conducts classroom, laboratory, and field investigations to explain phenomena or design solutions using appropriate tools and models. The student is expected to:

Lab Cleaning Methods for Biosafety

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