Radiation Safety
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…
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 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…
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…
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…
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…
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…
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…
Electrophoresis System Dynamics The apparatus in gel electrophoresis constitutes an electrical/thermodynamic system. The apparatus receives energy from the power source and releases energy as heat. The figure below shows a stylized representation of a typical…
The term “electrophoresis” refers simply to the movement of particles by an electric force. The first electrophoresis experiments were carried out on molecules in a conductive buffer solution, where the only force acting on the…