Electrophoresis - Color Icons2

FUNDAMENTAL PRINCIPLES OF ELECTROPHORESIS Articles

Buffer Additives-Hydrogen Bonding Agents

By National Diagnostics | August 12, 2011 | Comments Off on Buffer Additives-Hydrogen Bonding Agents

In most forms of electrophoresis, the solution perfusing the gel matrix typically contains one or more substances in addition to the buffer salts. Serving the purpose of modifying the properties of sample molecules, these additives…

Multiphasic Buffer Systems

By National Diagnostics | August 12, 2011 | Comments Off on Multiphasic Buffer Systems

Employing gel and buffer discontinuities to produce sharp separation among sample components, multiphasic electrophoresis design can improve the resolution of electrophoresis (especially protein electrophoresis). The system employs a separating gel in which the sample is…

Homogeneous Buffer Systems

By National Diagnostics | August 12, 2011 | Comments Off on Homogeneous Buffer Systems

In a homogeneous buffer system, the identity and concentration of buffer components are the same in the gel and the tanks. Most forms of DNA and RNA electrophoresis generally use homogeneous buffer systems. Electrophoresis of…

Electrophoresis Buffers-Choosing the Right Buffer

By National Diagnostics | August 12, 2011 | Comments Off on Electrophoresis Buffers-Choosing the Right Buffer

Several factors to consider when choosing a buffer include: 1) pKa value – A buffer should be chosen with a pKa that is very close to the desired pH, preferably within a half point. The…

The Polyacrylamide Matrix-Buffer Strength

By National Diagnostics | August 12, 2011 | Comments Off on The Polyacrylamide Matrix-Buffer Strength

The buffer system in electrophoresis controls the pH of the gel, preventing damage to sample molecules and, in certain cases, controlling the ionization state of the molecules. A second, though no less significant function, derives…

Electrophoresis Buffers–The Henderson-Hasselbalch Equation

By National Diagnostics | August 12, 2011 | Comments Off on Electrophoresis Buffers–The Henderson-Hasselbalch Equation

In its simplest form, a buffered solution contains a mixture of a weak acid and its conjugate base. The position of acid/base equilibrium is represented by the acid dissociation constant, Ka. This number is large…

The Agarose Matrix

By National Diagnostics | August 12, 2011 | Comments Off on The Agarose Matrix

A natural colloid extracted from seaweed, agarose is a linear polysaccharide made up of the repeating unit agarobiose, which consists of alternating units of 1,3-linked b-D-galactopyranose and 1,4-linked 3,6-anhydro-a-L-galactopyranose. Gels prepared from agarose have a…

The Polyacrylamide Matrix

By National Diagnostics | August 12, 2011 | Comments Off on The Polyacrylamide Matrix

Polyacrylamide gels are formed by the polymerization of acrylamide in an aqueous solution in the presence of small amounts of a bifunctional crosslinker. The crosslinker is usually methylenebisacrylamide (bis, or MBA). Polyacrylamide gels are formed…

The Electrophoresis Matrix

By National Diagnostics | August 12, 2011 | Comments Off on The Electrophoresis Matrix

In-gel electrophoresis the matrix forces sample components to separate by size, as they move through its porous structure. The matrix provides greater resistance to the movement of larger molecules. It also performs additional functions including…

The Mechanical and Electrical Dynamics of Gel Electrophoresis – Ohm’s Law

By National Diagnostics | August 10, 2011 | Comments Off on The Mechanical and Electrical Dynamics of Gel Electrophoresis – Ohm’s Law

Ohm’s Law: Relationships between electrical parameters Ohm’s law describes the relationship between the voltage, V, the current, I, and the resistance, R, in a DC circuit. A greater voltage produces a greater proportional current through…