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Silica Gel: A non-crystalline form of silicon oxide that has absorptive properties. It is commonly used as a desiccating agent and as a stationary phase for Chromatography. The fully hydrated form of silica gel has distinct properties and is referred to as Silicic acid.
 Science Education: Essentials of Organic Chemistry

Column Chromatography

JoVE Science Education

Source: Laboratory of Dr. Jimmy Franco - Merrimack College

Column chromatography is one of the most useful techniques for purifying compounds. This technique utilizes a stationary phase, which is packed in a column, and a mobile phase that passes through the column. This technique exploits the differences in polarity between compounds, allowing the molecules to be facilely separated.1 The two most common stationary phases for column chromatography are silica gel (SiO2) and alumina (Al2O3), with the most commonly used mobile phases being organic solvents.2 The solvent(s) chosen for the mobile phase are dependent on the polarity of the molecules being purified. Typically more polar compounds require more polar solvents in order to facilitate the passage of the molecules through the stationary phase. Once the purification process has been completed the solvent can be removed from the collected fractions using a rotary evaporator to yield the isolated material.

 Science Education: Essentials of Earth Science

Purification of a Total Lipid Extract with Column Chromatography

JoVE Science Education

Source: Laboratory of Jeff Salacup - University of Massachusetts Amherst

The product of an organic solvent extraction, a total lipid extract (TLE), is often a complex mixture of hundreds, if not thousands, of different compounds. The researcher is often only interested in a handful of compounds. The compounds of interest may belong to one of several classes of compounds, such as alkanes, ketones, alcohols, or acids (Figure 1), and it may be useful to remove the compound classes to which it does not belong in order to get a clearer view of the compounds you are interested in. For example, a TLE may contain 1,000 compounds, but the Uk'37 sea surface temperature proxy is based on only two compounds (alkenones) and the TEX86 sea surface temperature proxy is based on only four (glycerol dialkyl glycerol tetraethers). It would behoove the researcher to remove as many of the compounds they are not interested in. This makes the instrumental analysis of the compounds of interest (alkenones or GDGTs) less likely to be complicated by other extraneous compounds. In other cases, an upstream purification technique may have produced compounds you wish to now remove from the sample, such as the production of carboxylic acids during saponification in our

 JoVE Medicine

A Detailed Protocol for Perspiration Monitoring Using a Novel, Small, Wireless Device

1Wellness Promotion Science Center, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 2Advanced Research Center for Human Sciences, Waseda University, 3Department of Clinical Laboratory Science, Graduate School of Medical Science, Kanazawa University, 4Asanogawa General Hospital


JoVE 54837

 JoVE Engineering

The Evolution of Silica Nanoparticle-polyester Coatings on Surfaces Exposed to Sunlight

1School of Science, Faculty of Science, Engineering and Technology, Swinburne University of Technology, 2BlueScope Steel Research, 3Infrared Microspectroscopy Beamline, Australian Synchrotron, 4School of Science, College of Science, Engineering and Health, RMIT University


JoVE 54309

 JoVE Medicine

Detection and Genogrouping of Noroviruses from Children's Stools By Taqman One-step RT-PCR

1Laboratorio de Investigación y Desarrollo (LID), Universidad Peruana Cayetano Heredia, 2Bloomberg School of Public Health, Johns Hopkins University, 3Laboratorio de Diagnostico Molecular, Facultad de Medicina, University of Concepcion,Chile, 4University of California San Diego School of Medicine


JoVE 3232

 JoVE In-Press

Preparation of Giant Vesicles Exhibiting Visible-light-induced Morphological Changes

1Department of Applied Chemistry, School of Applied Science, National Defense Academy of Japan, 2Department of Applied Physics, School of Applied Science, National Defense Academy of Japan, 3Department of Materials Science and Technology, Faculty of Engineering, Niigata University

Video Coming Soon

JoVE 54817

 JoVE Biology

Combining Single-molecule Manipulation and Imaging for the Study of Protein-DNA Interactions

1LENS - European Laboratory for Non-linear Spectroscopy, University of Florence, 2Chemistry Research Laboratory, University of Oxford, 3Department of Biology, University of Florence, 4Department of Physics and Astronomy, University of Florence, 5National Institute of Optics-National Research Council, Italy, 6International Center of Computational Neurophotonics


JoVE 51446

 JoVE In-Press

Using RNA-sequencing to Detect Novel Splice Variants Related to Drug Resistance in In Vitro Cancer Models

1Department of Pediatric Oncology/Hematology, VU University Medical Center, 2Department of Hematology, VU University Medical Center, 3Department of Medical Oncology, VU University Medical Center, 4Department of Clinical Genetics, VU University Medical Center, 5Division of General and Transplant Surgery, Azienda Ospedaliera Universitaria Pisana, Universita’ di Pisa, 6Amsterdam Immunology and Rheumatology Center, VU University Medical Center, 7Princess Máxima Center for Pediatric Oncology, 8Cancer Pharmacology Lab, AIRC Start-Up Unit, University of Pisa, 9Institute of Nanoscience and Nanotechnology, CNR-Nano

Video Coming Soon

JoVE 54714

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