| cell electrophoresis | <technique> A method for estimating the surface charge of a cell by looking at its rate of movement in an electrical field. Almost all eukaryotic cells have a net negative surface charge. Measurement is complicated by the streaming potential at the wall of the chamber itself and by the fact that the cell is surrounded by a layer of fluid (see double layer). The electrical potential measured (the zeta potential) is actually some distance away from the plasma membrane. One of the more useful modifications is to systematically vary the pH of the suspension fluid to determine the pK of the charged groups responsible (mostly carboxyl groups of sialic acid). (26 Mar 1998) |
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| cell extracts | Preparations of cell constituents or subcellular materials, isolates, or substances. (12 Dec 1998) |
| cell fate | <embryology> Of an embryonic parent (progenitor) cell or cell type, the range and distribution of differentiated tissues formed by its daughter cells. For example: cells of the neural crest differentiate to form among other things) cells of the peripheral nervous system. (26 Mar 1998) |
| cell fractionation | <technique> Strictly this should mean the separation of homogeneous sets from a heterogeneous population of cells (by a method such as flow cytometry). The term is more frequently used to mean subcellular fractionation i.e. The separation of different parts of the cell by differential centrifugation, to give nuclear, mitochondrial, microsomal and soluble fractions. (26 Mar 1998) |
| cell-free extract | <cell culture> A liquid that is a mixture of the contents of a particular type of cell, sometimes the organelles are also filtered out of the liquid. (26 Mar 1998) |
| cell-free protein synthesis | <technique> An in vitro method to make proteins, using amino acids, the mRNA corresponding to the protein to be made, and a cell-free extract (the contents of a cell after removal of the cell wall and/or outer cell membranes) for other needed components and enzymes. (26 Mar 1998) |
| cell-free system | <cell culture, molecular biology> Any system in which a normal cellular reaction is reconstituted in the absence of cells for example in vitro translation systems that will synthesise protein from mRNA using a lysate of rabbit reticulocytes or wheat germ. A fractionated cell extract that maintains a biological function. A subcellular fraction isolated by ultracentrifugation or other separation techniques must first be isolated so that a process can be studied free from all of the complex side reactions that occur in a cell. The cell-free system is therefore widely used in cell biology. (12 Dec 1998) |
| cell fusion | <biology, embryology> Fusion of two previously separate cells occurs naturally in fertilization and in the formation of vertebrate skeletal muscle, but can be induced artificially by the use of Sendai virus or fusogens such as polyethylene glycol. Fusion may be restricted to cytoplasm or nuclei may fuse as well. A cell formed by the fusion of dissimilar cells is often referred to as a heterokaryon. (26 Mar 1998) |
| cell growth | <cell biology> Usually used to mean increase in the size of a population of cells though strictly should be reserved for an increase in cytoplasmic volume of an individual cell. (26 Mar 1998) |
| cell hybridization | Fusion of two or more dissimilar cells, leading to formation of a synkaryon. (05 Mar 2000) |
| cell hypoxia | A condition of decreased oxygen content at the cellular level. (12 Dec 1998) |
| cell inclusions | The residual elements of the cytoplasm that are metabolic products of the cell, e.g., pigment granules or crystals. Synonym: metaplasm. Storage materials such as glycogen or fat, engulfed material such as carbon or other foreign substances. See: inclusion bodies. (05 Mar 2000) |
| cell junction | <cell biology> Specialised junctions between cells. See: adherens junctions, desmosomes, tight junctions, gap junctions. (26 Mar 1998) |
| cell line | <cell culture> A cell line is a permanently established cell culture that will proliferate indefinitely given appropriate fresh medium and space. Lines differ from cell strains in that they have escaped the Hayflick limit and become immortalised. Some species, particularly rodents, give rise to lines relatively easily, whereas other species do not. No cell lines have been produced from avian tissues and the establishment of cell lines from human tissue is difficult. Many cell biologists would consider that a cell line is by definition already abnormal and that it is on the way towards becoming the culture equivalent of a neoplastic cell. (26 Mar 1998) |
| cell lineage | <cell culture, embryology> The lineage of a cell relates to its derivation from the undifferentiated tissues of the embryo. Committed embryonic progenitors give rise to a range of differentiated cells: in principle it should be possible to trace the ancestry lineage) of any adult cell. (26 Mar 1998) |