| agarose gel electrophoresis | <procedure> A type of electrophoresis that uses a matrix of highly purified agar to separate large nucleotides in size. (06 May 1997) |
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| aluminum hydroxide gel | A suspension containing Al2O3, mainly in the form of aluminum hydroxide, used as an antacid; a dried form, with the same use, is obtained by drying the product of interaction in aqueous solution of an aluminum salt with ammonium or sodium carbonate. (05 Mar 2000) |
| aluminum phosphate gel | An aqueous suspension of between 4.0 and 5.0% of aluminum phosphate; used as an antacid. (05 Mar 2000) |
| bag-gel implant | An implant composed of a silicone rubber bag containing a silicone gel; used in augmentation mammaplasty. (05 Mar 2000) |
| gel | Jelly like material formed by the coagulation of a colloidal liquid. Many gels have a fibrous matrix and fluid filled interstices: gels are viscoelastic rather than simply viscous and can resist some mechanical stress without deformation. Examples are the gels formed by large molecules such as collagen (and gelatin), agarose, acrylamide and starch. (18 Nov 1997) |
| gel electrophoresis | <molecular biology> Electrophoresis using a gel supporting phase. Usually applied to systems where the gel is based on polyacrylamide. See: electrophoresis. (05 May 1997) |
| 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 | <molecular biology> An important method for separating molecules according to molecular size by percolating the solution through beads of solvent permeated polymer that has pores of similar size to the solvent molecules. Unlike a continous filter that retards flow according to molecular size, separation is achieved because molecules that can enter the beads take a longer path (i.e. Are retarded) than those that cannot. Typical gels for protein separation are made from polyacrylamide or from flexible (Sephadex) or rigid (agarose, Sepharose) sugar polymers. The size separation range is determined by the degree of cross linking of the gel. (05 May 1997) |
| gel filtration chromatography | See: gel filtration. (05 Mar 2000) |
| gel retardation assay | A lab technique used to find out if there are proteins binding a fragment of DNA (in a DNA-protein complex) by watching how fast the DNA fragment moves through an electric field and seeing whether it moves slower when a particular protein is also present. (09 Oct 1997) |
| gel structure | Brush heap structure of fibrils giving firmness to hydrocolloids. (05 Mar 2000) |
| gel transfer | Any lab technique used to transfer substances which had been separated using gel electrophoresis from the gel to a membrane for further processing or analysis. For example: any type of blotting. (09 Oct 1997) |
| pharmacopeial gel | A suspension, in a water medium, of an insoluble drug in hydrated form wherein the particle size approaches or attains colloidal dimensions. (05 Mar 2000) |
| chromatography, gel | Chromatography on non-ionic gels without regard to the mechanism of solute discrimination. (12 Dec 1998) |
| colloidal gel | A colloid that has developed resistance to flow because of chemical or thermal change. (05 Mar 2000) |