| DGGE | denaturating gradient gel electrophoresis |
|---|---|
| ECPOG | electrochemical potential gradient |
| GE | gastric empyting; gastroemotional; gastroenteritis; gastroenterology; gastroenterostomy; gastroesoph... |
| GEPG | gastroesophageal pressure gradient |
| GGE | generalized glandular enlargement; gradient gel electrophoresis |
| density gradient centrifugation | <technique> High-speed centrifugation inwhich molecules float at a point wheretheir density equals that in a gradient of cesium chloride or sucrose. (12 Jan 1998) |
|---|---|
| systolic gradient | The difference in pressure during systole between two communicating cardiovascular chambers, e.g., between the left ventricle and aorta in aortic stenosis. (05 Mar 2000) |
| electrochemical gradient | A measure of the tendency of an ion to move passively from one point to another, taking into consideration the differences in its concentration and in the electrical potentials between the two points; commonly expressed as the additional voltage needed to achieve equilibrium. (05 Mar 2000) |
| ficoll gradient | A density gradient of ficoll (synthetic sucrose polymer) in solution, where concentration of the ficoll varies continuously through the solution. It is often used to separate different types of cells from each other during the process of sedimentation. (09 Oct 1997) |
| field gradient | In magnetic resonance imaging, a magnetic field that varies with location, superimposed on the uniform field of the magnet, to alter the resonant frequency of nuclei and allow recovery of their spatial position. Synonym: field gradient. (05 Mar 2000) |
| absorption chromatography | <investigation> Techniques for separating molecules based on differential absorption and elution. Term for separation methods involving flow of a fluid carrier over a nonmobile absorbing phase. (18 Nov 1997) |
| adsorption chromatography | Chromatography in which separation of substances is achieved by the difference in degree of adsorption of the compounds to a stationary phase. (05 Mar 2000) |
| affinity chromatography | <investigation> A technique of analytical chemistry used to separate and purify a biological molecule from a mixture, based on the attraction of the molecule of interest to a particular ligand which has been previously attached to a solid, inert substance. The mixture is passed through a column containing the ligand attached to the stationary substance, so that the molecule of interest stays within the column while the rest of the mixture continues through to the end. Then, a different chemical is flushed through the column to detach the molecule from the ligand and bring it out separately from the rest of the mixture. (09 Feb 1998) |
| gas chromatography | <technique> A chromatographic technique (a type of column chromatography) in which the stationary phase is solid while the mobile phase is gaseous samples. The gaseous samples are separated based on their different adsorption ability to the solid phase. (09 Oct 1997) |
| gas-liquid chromatography | <technique> A chemistry lab technique, a type of column chromatography, used to separate the components of a mixed substance. The substance is held stationary by an inert solid coated with an inert liquid which is not likely to evaporate (i.e. Is nonvolatile), while a gas (called an eluant) flows past it bringing out the components one at a time. (09 Oct 1997) |
| paper chromatography | <technique> Separation method in which filter paper is used as the support. A type of chromatography in which the stationary phase is a sheet of special-grade filter paper. It is in all other aspects similar to thin-layer chromatography. Not a very sensitive method, but historically important as one of the first methods available for separating natural compounds. (07 Mar 2000) |
| gel exclusion chromatography | <investigation> A lab technique, a type of column chromatography, used to separate the components of a mixture by molecular size and to collect the molecules which are larger than a certain size. It is similar to gel filtration, small molecules are slowed or trapped by the pores in the gel beads filling the column, while large molecules, too large to fit into the pores, slide past the beads and get to the bottom of the column first. at this point, the large molecules are collected. Gel exclusion refers to the maximum size of molecule which will fit into the gel bead pores, and this lab technique is used to collect the molecules in the mixture which are larger than, or excluded from, the pores. (09 Oct 1997) |
| gel filtration chromatography | See: gel filtration. (05 Mar 2000) |
| partition chromatography | The separation of similar substances by repeated divisions between two immiscible liquids, so that the substances, in effect, cross the partition between the liquids in opposite directions; where one of the liquids is bound as a film on filter paper, the process is termed paper partition chromatography or paper chromatography. (05 Mar 2000) |
| reversed phase chromatography | A form of partitionary chromatography in which the stationary phase is more polar than the mobile phase. (05 Mar 2000) |