| fermenter | <apparatus> In biotechnology, a fermenter is the container in which host cells containing recombinant DNA are grown. Ferments can vary in size from less than a liter for experimental systems to thousands of liters for commercial systems. The one constant is that they are closed tanks. (14 Nov 1997) |
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| fermentor | A device used to grow large amounts of bacteria in liquid culture. The device generally can hold more than 10 litres of liquid growth medium, has a heater to provide constant temperature, and has an agitator for aeration. (09 Oct 1997) |
| fermium | <chemical> Fermium. A man-made radioactive actinide with atomic symbol fm, atomic number 100, and atomic weight 257. Its known isotopes range from 244-254 and 256-258. Its valence can be +2 or +3. Like einsteinium, it was discovered in 1952 in the debris from a thermonuclear explosion. Chemical name: Fermium (12 Dec 1998) |
| fern | <botany> An order of cryptogamous plants, the Filices, which have their fructification on the back of the fronds or leaves. They are usually found in humid soil, sometimes grow epiphytically on trees, and in tropical climates often attain a gigantic size. The plants are asexual, and bear clustered sporangia, containing minute spores, which germinate and form prothalli, on which are borne the true organs of reproduction. The brake or bracken, the maidenhair, and the polypody are all well known ferns. Christmas fern. See Christmas. <botany> Climbing fern The European goatsucker. The short-eared owl. Fern shaw, a fern thicket. Origin: AS. Fearn; akin to D. Varen, G. Farn, farnkraut; cf. Skr. Parna wing, feather, leaf, sort of plant, or Lith. Papartis fern. Source: Websters Dictionary (01 Mar 1998) |
| fern allies | <botany> A group of nonflowering vascular plants comprised of club mosses (Family Lycopodiaceae), small club mosses (Family Selaginellaceae) and quillworts (Family Isoetaceae). (09 Oct 1997) |
| fern test | A test for oestrogenic activity; cervical mucus smears form a fern pattern at those times when oestrogen secretion is elevated, as at the time of ovulation; a test to detect ruptured amniotic membranes. (05 Mar 2000) |
| Fernandez reaction | A delayed hypersensitivity lepromin reaction, similar to a tuberculin reaction, at the site of intradermal injection of Dharmendra antigen in a lepromin test. (05 Mar 2000) |
| Fernbach flask | A flask used in microbial fermentations where a large surface area of the liquid substrate is required. (05 Mar 2000) |
| Fernbach, Auguste | <person> French microbiologist, 1860-1939. See: Fernbach flask. (05 Mar 2000) |
| ferning | A term used to describe the pattern of arborization produced by cervical mucus, secreted at midcycle, upon crystallization, which resembles somewhat a fern or a palm leaf. (05 Mar 2000) |
| fernticle | A freckle on the skin, resembling the seed of fern. Source: Websters Dictionary (01 Mar 1998) |
| Ferrata's cell | A primitive mesenchymal cell believed to be capable of developing into all types of blood cells, including monocytes, and into histiocytes. Synonym: Ferrata's cell, haematohistioblast. Origin: haemo-+ G. Histion, web, + blastos, germ (05 Mar 2000) |
| ferrate | <chemistry> A salt of ferric acid. Origin: L. Ferrum iron. Source: Websters Dictionary (01 Mar 1998) |
| ferratin | Sodium iron albuminate;a haematinic. (05 Mar 2000) |
| ferredoxin | <protein> Low molecular weight iron sulphur proteins that transfer electrons from one enzyme system to another without themselves having enzyme activity. (18 Nov 1997) |