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Acetic Acid: Product of the oxidation of ethanol and of the destructive distillation of wood. It is used locally, occasionally internally, as a counterirritant and also as a reagent. (Stedman, 26th ed)

Lewis Acid-Base Interaction in Ph3P-BH3

JoVE 10316

Source: Tamara M. Powers, Department of Chemistry, Texas A&M University 


One of the goals of chemistry is to use models that account for trends and provide insights into the properties of reactants that contribute to reactivity. Substances have been classified as acids and bases since the time of the ancient Greeks, but the…

 Inorganic Chemistry

Introduction to Titration

JoVE 5699

Source: Laboratory of Dr. Yee Nee Tan — Agency for Science, Technology, and Research


Titration is a common technique used to quantitatively determine the unknown concentration of an identified analyte.1-4 It is also called volumetric analysis, as the measurement of volumes is critical in titration. There are many types of titrations…

 General Chemistry

Safe Handling of Mineral Acids

JoVE 10370

Source: Robert M. Rioux & Taslima A. Zaman, Pennsylvania State University, University Park, PA


A mineral acid (or inorganic acid) is defined as a water-soluble acid derived from inorganic minerals by chemical reaction as opposed to organic acids (e.g. acetic acid, formic acid). Examples of mineral acids…

 Lab Safety

Transformation of E. coli Cells Using an Adapted Calcium Chloride Procedure

JoVE 10515

Source: Natalia Martin1, Andrew J. Van Alst1, Rhiannon M. LeVeque1, and Victor J. DiRita1
1 Department of Microbiology and Molecular Genetics, Michigan State University


Bacteria have the ability to exchange genetic material (DeoxyriboNucleic Acid, DNA) in a process known as horizontal gene transfer. Incorporating exogenous DNA…

 Microbiology

Cleaning Glassware

JoVE 10342

Source: Vy M. Dong and Daniel Kim, Department of Chemistry, University of California, Irvine, CA


Organic synthesis is about transforming a readily available reagent into a more valuable product. Having clean glassware is crucial for the efficiency of this process. Dirty glassware can potentially affect the reaction and make isolation of…

 Organic Chemistry II

Visualizing Soil Microorganisms via the Contact Slide Assay and Microscopy

JoVE 10053

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - Arizona University
Demonstrating Author: Bradley Schmitz


Soil comprises the thin layer at the earth’s surface, containing biotic and abiotic factors that contribute to life. The abiotic portion includes inorganic particles ranging in size and shape that determine…

 Environmental Microbiology

Separation of Mixtures via Precipitation

JoVE 5558

Source: Laboratory of Dr. Ana J. García-Sáez — University of Tübingen


Most samples of interest are mixtures of many different components. Sample preparation, a key step in the analytical process, removes interferences that may affect the analysis. As such, developing separation techniques is an important endeavor not…

 Organic Chemistry

High-Performance Liquid Chromatography (HPLC)

JoVE 10156

Source: Dr. Paul Bower - Purdue University


High-performance liquid chromatography (HPLC) is an important analytical method commonly used to separate and quantify components of liquid samples. In this technique, a solution (first phase) is pumped through a column that contains a packing of small porous particles with a second phase bound to …

 Analytical Chemistry

Method of Standard Addition

JoVE 10201

Source: Laboratory of Dr. Paul Bower - Purdue University


The method of standard additions is a quantitative analysis method, which is often used when the sample of interest has multiple components that result in matrix effects, where the additional components may either reduce or enhance the analyte absorbance signal. That results in…

 Analytical Chemistry

Efficiency of Liquid-liquid Extraction

JoVE 10426

Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA


Liquid-liquid extraction (LLE) is a separation technique used instead of distillation when either: (a) the relative volatilities of the compounds to be separated are very similar; (b) one or more of the mixture…

 Chemical Engineering

Soil Nutrient Analysis: Nitrogen, Phosphorus, and Potassium

JoVE 10077

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University


In this experiment, three soil macronutrients are chemically extracted, combined with color-based reagents, then analyzed using color to determine the nutrient concentration present in the soil sample.


Nitrogen, phosphorus, and…

 Environmental Science

Determining the Empirical Formula

JoVE 10181

Source: Laboratory of Dr. Neal Abrams - SUNY College of Environmental Science and Forestry


Determining the chemical formula of a compound is at the heart of what chemists do in the laboratory every day. Many tools are available to aid in this determination, but one of the simplest (and most accurate) is the determination of the empirical…

 General Chemistry

Ozonolysis of Alkenes

JoVE 10339

Source: Vy M. Dong and Zhiwei Chen, Department of Chemistry, University of California, Irvine, CA


This experiment will demonstrate an example of an ozonolysis reaction to synthesize vanillin from isoeugenol (Figure 1). Ozonolysis of alkenes, an oxidation reaction between ozone and an alkene, is a common method to prepare…

 Organic Chemistry II

SEM Imaging of Biological Samples

JoVE 10492

Source: Peiman Shahbeigi-Roodposhti and Sina Shahbazmohamadi, Biomedical Engineering Department, University of Connecticut, Storrs, Connecticut


A scanning electron microscope (SEM) is an instrument that uses an electron beam to nondestructively image and characterize conductive materials in a vacuum. As an analogy, an…

 Biomedical Engineering

Hydrogenation

JoVE 10350

Source: Vy M. Dong and Zhiwei Chen, Department of Chemistry, University of California, Irvine, CA


This experiment will demonstrate the hydrogenation of chalcone as an example of an alkene hydrogenation reaction (Figure 1). In this experiment, palladium on carbon (Pd/C) will be used as a heterogeneous catalyst for the…

 Organic Chemistry II

Dye-sensitized Solar Cells

JoVE 10328

Source: Tamara M. Powers, Department of Chemistry, Texas A&M University


Today's modern world requires the use of a large amount of energy. While we harness energy from fossil fuels such as coal and oil, these sources are nonrenewable and thus the supply is limited. To maintain our global lifestyle, we must extract energy from…

 Inorganic Chemistry

Rotary Evaporation to Remove Solvent

JoVE 5501

Source: Dr. Melanie Pribisko Yen and Grace Tang — California Institute of Technology


Rotary evaporation is a technique most commonly used in organic chemistry to remove a solvent from a higher-boiling point compound of interest. The rotary evaporator, or "rotovap", was invented in 1950 by the chemist Lyman C. Craig. The…

 Organic Chemistry

Epithelial Cell Repopulation and Preparation of Rodent Extracellular Matrix Scaffolds for Renal Tissue Development

1Comprehensive Transplant Center, Feinberg School of Medicine, Northwestern University, 2Department of Surgery, Feinberg School of Medicine, Northwestern University, 3Department of Biomedical Engineering, Northwestern University, 4Simpson Querrey Institute for BioNanotechnology in Medicine, Northwestern University, 5Department of Internal Medicine, University of New Mexico HSC, 6Department of Pathology, University of New Mexico HSC, 7Department of Chemical and Biological Engineering, Northwestern University, 8Chemistry of Life Processes Institute, Northwestern University, 9Department of Surgery, Jesse Brown VA Medical Center

JoVE 53271

 Bioengineering

Techniques for the Evolution of Robust Pentose-fermenting Yeast for Bioconversion of Lignocellulose to Ethanol

1Bioenergy Research Unit, National Center for Agricultural Utilization Research, 2Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, 3Chemical Engineering and Material Science, Great Lakes Bioenergy Center, Michigan State University

JoVE 54227

 Bioengineering
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