Gel electrophoresis

related topics
{acid, form, water}
{math, energy, light}
{system, computer, user}
{rate, high, increase}
{line, north, south}
{album, band, music}
{work, book, publish}
{math, number, function}

Gel electrophoresis is a technique used for the separation of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), or protein molecules using an electric field applied to a gel matrix.[1] DNA Gel electrophoresis is usually performed for analytical purposes, often after amplification of DNA via PCR, but may be used as a preparative technique prior to use of other methods such as mass spectrometry, RFLP, PCR, cloning, DNA sequencing, or Southern blotting for further characterization.

Contents

Separation

The term "gel" in this instance refers to the matrix used to contain, then separate the target molecules. In most cases, the gel is a crosslinked polymer whose composition and porosity is chosen based on the specific weight and composition of the target to be analyzed. When separating proteins or small nucleic acids (DNA, RNA, or oligonucleotides) the gel is usually composed of different concentrations of acrylamide and a cross-linker, producing different sized mesh networks of polyacrylamide. When separating larger nucleic acids (greater than a few hundred bases), the preferred matrix is purified agarose. In both cases, the gel forms a solid, yet porous matrix. Acrylamide, in contrast to polyacrylamide, is a neurotoxin and must be handled using appropriate safety precautions to avoid poisoning. Agarose is composed of long unbranched chains of uncharged carbohydrate without cross links resulting in a gel with large pores allowing for the separation of macromolecules and macromolecular complexes.

"Electrophoresis" refers to the electromotive force (EMF) that is used to move the molecules through the gel matrix. By placing the molecules in wells in the gel and applying an electric field, the molecules will move through the matrix at different rates, determined largely by their mass when the charge to mass ratio (Z) of all species is uniform, toward the anode if negatively charged or toward the cathode if positively charged.[2]

Full article ▸

related documents
Erbium
Neodymium
Standard electrode potential (data page)
Tertiary structure
Island of stability
Indium
Gallium
Ununtrium
Californium
Ethylene glycol
Coenzyme Q - cytochrome c reductase
Toluene
Organelle
Organic acid
Solder
Nucleotide
Eutectic point
Tartaric acid
Borax
Nucleolus
Dolomite
Heme
Oxidation state
Electron counting
Melting point
Pyridine
Ribosome
Pyroxene
Protease
Americium