Ch 4 Flashcards
(30 cards)
the migration of charged solutes or particles in an electrical field.
Electrophoresis
refers to the migration of small ions
Iontophoresis
is the migration of charged macromolecules in a porous support medium such as paper, cellulose acetate, or agarose gel film
Zone Electrophoresis
film is soaked in buffer, the air spaces fill with electrolyte and the film becomes pliable.
Cellulose acetate
another widely used supporting medium. Used as a purified fraction of agar, it is neutral and, therefore, does not produce electroendosmosis
Agarose Gel
-involves separation of protein on the basis of charge and molecular size. Separates serum proteins into 20 or more fractions rather than the usual 6 fractions separated by cellulose acetate or agarose. It is widely used to study individual proteins
Polyacrylamide Gel
separates proteins on the basis of surface charge and molecular size, as does polyacrylamide gel. The procedure is not widely used because of technical difficulty in preparing the gel.
Starch gel
The movement of buffer ions and solvent relative to the fixed support is called
Endosmosis or Electroendosmosis
Charged proteins migrate through a support medium that has a continuous pH gradient.
Isoelectric focusing
is used in the clinical laboratory to characterize monoclonal proteins in
serum, urine, or cerebrospinal fluid (CSF).
Immunofixation electrophoresis
separation is performed in narrow-bore, fused silica capillaries (inner diameter 25 to 75 um).
Capillary electrophoresis
is the bulk flow of liquid toward the cathode upon application of an electric field, and it is superimposed on electrophoretic migration
Electroosmotic Flow (EOF)
This electrophoresis assay combines two different electrophoresis dimensions to separate proteins from complex matrices such as serum or tissue.
Two-Dimensional Electrophoresis
is the principle of measuring the concentration of solute particles in a solution using one of the four colligative properties discussed below
Osmometry
enables the study of the binding of ligands to surface receptors such as membrane proteins in real time.
Surface plasmon resonance
a similar label-free technique that uses sensor tips instead of a flat metal surface.
Biolayer interferometry
refers to the group of techniques used to separate complex mixtures on the basis of different physical interactions between the individual compounds and the stationary phase of the system
Chromatography
also known as liquid- solid chromatography, is based on the competition between the sample and the mobile phase for adsorption sites on the solid stationary phase.
Adsorption
also referred to as liquid- liquid chromatography. Separation of solute is based on relative solubility in an organic (nonpolar) solvent and an aqueous (polar) solvent. In its simplest form, it is performed in a separatory funnel
Partition
a variation of liquid-solid chromatography, is used to separate solute molecules on the basis of size and shape. The chromatographic column is packed with porous material
Steric exclusion
used to remove interfering substances from a solution, to concentrate dilute ion solutions, and to separate mixtures of charged molecules, such as amino acids. Changing pH and ionic concentration of the mobile phase allows
Ion exchange chromatography
a variant of column chromatography. A thin layer of sorbent, such as alumina, silica gel, cellulose, or cross-linked dextran, is uniformly coated on a glass or plastic plate.
It is most commonly used as a semiquantitative screening test.
Thin-Layer Chromatography
uses pressure for fast separations, controlled temperature, inline detectors, and gradient elution techniques.
High Performance Liquid Chromatography (HPLC)
forces the mobile phase through the column at a much greater velocity than that accomplished by gravity flow columns and includes pneumatic, syringe, reciprocating, or hydraulic amplifier pumps.
Pumps
