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. 化学试剂
<ol>
	<li>液态化学品 
	液体消毒剂广泛用于实验室去污染。液体消毒剂的效果取决于多种因素，例如消毒剂的化学性质、浓度和用量、作用时间以及温度。需注意，并非所有液体消毒剂都适用于各种情况。应根据检测到的微生物种类，结合以下标准选择合适的消毒剂： 
	a. 污染微生物的类型：不同微生物对消毒剂的抗性不同。例如，细菌芽孢比亲脂性病毒具有更强的化学抗性。 
	b. 蛋白质类物质的含量：例如，高蛋白材料会吸收并中和某些化学消毒剂，如甲醛和季铵盐化合物。 
	c. 有机物含量：例如，在肥皂和洗涤剂存在的情况下，季铵盐类化合物的效力会降低。 
	d. 其他重要因素包括所用消毒剂的化学性质、浓度、用量、pH值、作用温度和毒性。 
	注意：使用化学消毒剂时，务必穿戴适当的个人防护装备。
	<ol>
		<li>低水平消毒剂 
		A. 季铵盐（QA）化合物：（如苯扎氯铵、氯化铵） 
		• 对革兰氏阳性菌、革兰氏阴性菌和包膜病毒有效。 
		• 对无包膜病毒、真菌和细菌芽孢无效。 
		• 含有 NH4+ 并与带负电荷的表面具有良好的接触性，使其成为优良的清洁剂。 
		• 毒性较低，但长时间接触可能引起刺激。 
		• 常用于地面、家具和墙壁等非关键表面。 
		B. 酚类：（基于邻苯酚酸酯的化合物） 
		• 对细菌有效，尤其对革兰氏阳性菌和有包膜病毒有效。 
		• 对无包膜病毒和芽孢无效。 
		• 与有机材料兼容。 
		• 毒性较低，但长时间暴露可能引起刺激。 
		• 常用于医院环境和实验室台面。</li>
		<li>中效消毒剂 
		A. 醇类（如乙醇和异丙醇） 
		• 对革兰氏阳性菌、革兰氏阴性菌和包膜病毒有效。 
		• 对芽孢无效，对无包膜病毒效果有限。 
		• 最佳浓度范围为60%–90%。当稀释至50%以下时，活性迅速下降。 
		• 常用于医疗环境。 
		• 醇类易燃且易快速挥发。 
		B. 卤素类生物杀菌剂：（含氯化合物和碘附） 
		氯化合物 
		• 次氯酸盐是最常用的含氯消毒剂。 
		• 对包膜病毒和非包膜病毒、真菌、细菌及藻类均有效。 
		• 对芽孢无效。 
		• 有机物可使其迅速失活。 
		• 由于氧化性强，降解迅速。 
		C. 碘附剂：碘附剂是碘与助溶剂或载体的结合物；该复合物可作为碘的缓释储存库，并在水溶液中释放少量游离碘。 
		• 对细菌、芽孢和真菌有效。 
		• 需要较长的接触时间。 
		• 在有机物存在时无效。 
		• 常用于消毒剂、血培养瓶及医疗器械。</li>
		<li>高水平消毒剂 
		A. 氧化剂和酸：（过氧化氢，过氧乙酸） 
		该效应并不仅仅依赖于pH值。例如，尽管解离常数较低，弱有机酸的作用仍强于无机酸。 
		过氧化氢： 
		• 对有包膜和无包膜病毒、营养型细菌、真菌及细菌芽孢均有效。 
		• 常用于清洁伤口和消毒环境表面的防腐剂。 
		• 高浓度对组织有害。 
		过氧乙酸 
		• 对所有微生物均有效，作用迅速。 
		• 在有机物存在及低温条件下仍有效。 
		• 安全，无有害分解产物。 
		• 不适用于金属，因可能导致腐蚀。 
		• 常用于自动化设备中对医疗器械、外科器械和牙科器械进行灭菌。 
		B. 醛类（甲醛，戊二醛） 
		甲醛： 
		• 在气态和液态下均可用作消毒剂和灭菌剂。 
		• 常以37%的水溶液形式使用，称为甲醛溶液（formalin）。 
		• 对细菌、真菌、病毒和孢子均有效。 
		• 具有危害性，8小时加权暴露限值为0.75 ppm。 
		• 聚合态固体甲醛（多聚甲醛）也是一种强效消毒剂。 
		戊二醛 
		• 比甲醛有效10倍。 
		• 对营养型细菌、芽孢和病毒有效。 
		• 用于对设备进行灭菌。 
		• 在有机物存在的情况下仍然有效。 
		• 有害，上限阈值限值为 0.2 ppm，避免皮肤接触。</li>
	</ol>
	</li>
	<li>气体或蒸气 
	消毒剂的蒸气和气体包括二氧化氯、环氧乙烷、过氧化氢、过氧乙酸， 等等这些气体和蒸汽在封闭系统（如生物安全柜和动物房设施）中表现出优异的消毒性能。然而，为确保安全，必须严格控制温度、湿度以及惰性气体（若具可燃性）的条件。这些气体或蒸汽被用于医院和商业设施中，需在封闭系统内对温度、湿度和浓度进行精确控制。</li>
</ol>
2. 热量
<ol>
	<li>干热 
	干热法需在合适的烘箱中，于160–170 °C条件下持续2–4小时。该方法常用于玻璃器皿或其他非多孔性导热材料的灭菌。然而，对于隔热材料或热敏感材料则无效。</li>
	<li>湿热 
	湿热灭菌又称高压蒸汽灭菌，通常在至少120 °C条件下持续30–60分钟。高压蒸汽灭菌是最便捷且可靠的灭菌方法，可有效快速杀灭大多数形式的微生物。由于所需时间更短、温度更低，湿热灭菌比干热灭菌更高效。</li>
</ol>
3. 辐射
<ol>
	<li>电离辐射 
由于与辐射安全相关的潜在问题，电离辐射通常不用于一般实验室的灭菌。</li>
	<li>非电离辐射（紫外线，UV） 
紫外线因其强大的微生物灭活能力，通常用于空气、水和表面的去污。紫外线也广泛应用于生物安全柜中。紫外线的波长范围为250 nm至270 nm，其中265 nm为最佳波长。然而，紫外线灯的强度会随时间下降，因此需要在一定时间后进行维护以保持其功率。此外，使用紫外线时需采取预防措施，因为它可能对眼睛或皮肤造成灼伤。</li>
</ol>

为避免感染传播并维持实验室生物安全，定期进行实验室去污染至关重要。目前有三种可用方法，包括化学法、热力法和辐射法。每种方法各有其优势及适用场景。了解实验室环境中微生物的类型，有助于选择合适的去污染方法。在实施去污染程序期间，应采取适当的安全防护措施。

实验室生物安全去污

Robert M. Rioux 和 Zhifeng Chen，宾夕法尼亚州立大学，University Park，宾夕法尼亚州
去污染是实验室生物安全的关键环节，因为实验室中微生物污染的积累可能导致疾病的传播。去污染的程度可分为消毒和灭菌两类。消毒旨在清除实验台面或设备上除细菌芽孢以外的所有致病性微生物；而灭菌则旨在彻底杀灭所有微生物生命形式。目前可用的方法包括化学试剂、热力和辐射等，具体方法的选择取决于所需的去污染程度、污染物中微生物的浓度、有机物的存在情况以及待清洁设备或表面的类型。每种方法均有其优势，同时也需采取相应的安全防护措施，以避免潜在危害。

Robert M. Rioux 和 Zhifeng Chen，宾夕法尼亚州立大学，University Park，PA  
去污是实验室生物安全的关键环节，因为……

实验室空间的去污染对于防止微生物积聚和扩散至关重要，因为微生物可能导致疾病的传播。去污染分为两类：消毒和灭菌。消毒是指清除实验室表面和设备上几乎所有病原微生物，但微生物芽孢除外。而灭菌则是一种更为彻底的过程，可消除所有微生物生命形式。去污采用多种方法进行，例如化学试剂、热或辐射。方法的选择取决于污染程度以及污染物的类型和浓度。本视频将介绍去污的类型，以及对机器、表面和设备进行消毒和灭菌的操作程序。在建立去污染程序之前，必须确定微生物的种类、浓度和位置。微生物的种类包括革兰氏阳性菌或阴性菌、病毒、真菌、细菌芽孢和藻类。确定微生物种类后，应选择合适的消毒剂。在选择去污染方法时，必须考虑消毒剂的有效性，而有效性取决于其化学成分、用量、浓度、作用时间以及温度等因素。现在我们已经讨论了如何选择去污染方法，接下来让我们探讨实际操作中使用的各种类型。液体化学品分为三个等级，即低效、中效和高效消毒剂。无论选择哪一种，在处理危险物质时都必须佩戴适当的个人防护装备。大多数非致病性微生物仅需使用低水平消毒剂，这类消毒剂毒性较低，但长时间接触会引起刺激。常见的低水平消毒剂包括季铵盐类化合物，如苯扎氯铵和氯化铵，以及酚类化合物，如邻苯基苯酚和氯二甲酚。对于更难杀灭的微生物的去污染，从医疗保健到实验室等各个领域均使用基于酒精的化学试剂。此外，基于卤素的化合物，如次氯酸盐和碘附，常被用作医疗器械的抗菌剂和消毒剂。然而，这些试剂需要较长的接触时间，且在有机物存在时其有效性会降低。如果需要对所有微生物进行去污染，则使用高水平消毒剂，此类消毒剂可分为氧化剂、酸类和醛类。过氧化氢等氧化剂作用迅速，常用于伤口清洁的消毒剂以及对实验台等环境表面进行消毒。但需注意，接触高浓度的过氧化氢可能对组织和呼吸道有害。过氧乙酸通常用于对自动化设备进行消毒，并对医疗、外科和牙科器械进行灭菌。过氧乙酸及其他氧化剂的优点是作用时间短；然而，由于酸类可能腐蚀金属，因此其对需消毒材料的适用性可能受到限制。另一方面，醛类物质（如甲醛或戊二醛）虽不具腐蚀性，但仍具有危害性。这些化学品可用于对多种设备进行灭菌，但存在作用时间较长的缺点。除了液体化学品外，气体化学品也可用于去污。二氧化氯和环氧乙烷等气体，以及气化的过氧化氢和过氧乙酸，常被用于清除生物安全柜等密闭设备中的细菌、病毒和孢子。除了化学品之外，热量也是一种常见的用于病原体去污染的物理因子。热有两种形式。“干热”在160至170摄氏度条件下持续2至4小时，用于对玻璃器皿进行消毒，但不适用于热敏感材料。而“湿热”又称高压蒸汽灭菌，是在高压条件下将样品和设备加热至仅120摄氏度，持续30至60分钟。除了热力之外，波长范围为250至270纳米的紫外线辐射也常用于去污。该方法对细菌和病毒有效，但对孢子无效，可用于空气、水和表面（如生物安全柜内）的去污。此外，该波段的紫外线可引起皮肤和眼睛灼伤，因此应穿戴适当的个人防护装备。您刚刚观看了 JoVE 关于实验室安全去污染的简介视频。现在您应该了解了各种微生物污染物的类型、如何选择合适的方法，以及可用的消毒和灭菌类型。感谢观看！

Education

教育

JoVE Science Education

Basic Biology

基础生物学

Lab Safety

实验室安全

实验室生物安全净化

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

operation-of-high-pressure-reactor-vessels

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...

decontamination for laboratory 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.

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

本系列提供了使用危险材料和设备时应遵循的安全指导原则。它涵盖了个人防护装备，电气安全和一般应急指南等普遍主题，以及化学和生物实验室的一些特定安全程序。

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 ...

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

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 ...

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 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

Description

Transcript

More videos by Standards