medium

Wavelength

... factor equal to the refractive index n of the medium but the frequency of the wave is unchanged. The wa...ngths of electromagnetic radiation, no matter what medium they are travelling through, are usually quoted in terms of the vacuum wavelength, although this is ...

Tobacco mosaic virus

...nck showed that a filtered, bacteria-free culture medium still contained the infectious agent. The first concrete evidence for its existence was given by Dmitri Ivanowski in 1892. In 1935, Wendell Meredith Stanley crystallized the virus for electron microscopy and showed that it remains active even af...

Tobacco mosaic virus

...nck showed that a filtered, bacteria-free culture medium still contained the infectious agent. The first concrete evidence for its existence was given by Dmitri Ivanowski in 1892. In 1935, Wendell Meredith Stanley crystallized the virus for electron microscopy and showed that it remains active even af...

Stem cell

...taminated with nonhuman molecules from the culture medium used to grow the cells, for example, mouse cells and other animal cells. The nonhuman cell-surface sialic acid can compromise the potential uses of the embryonic stem cells in humans--according to scientists at the University of California, San Dieg...

Semen

...al plasma is to provide a nutritive and protective medium for the spermatozoa during their journey through the female reproductive tract. The normal enviroment of the vagina is a hostile one for sperm cells, it is very acidic (from the native microflora producing lactic acid ), viscous, and patrolled by im...

Blood plasma

...oteins , and mineral salts. It serves as transport medium for glucose , lipids , hormones , products of m...aric conditions.) It is the storage and transport medium of clotting factors and its protein content is necessary to maintain the oncotic pressure of the b...

Photon

...material, photons couple to the excitations of the medium and behave differently. These excitations can of...excitations (that is, the photon gets absorbed and medium excited, involving the creation of a quasi-particle) and vice versa (the quasi-particle transforms b...

Phosphorylation

... Other kinds ATP , the "high-energy" exchange medium in the cell, is synthesized in the mitochondrion by addition of a third phosphate group to ADP in a process referred to as oxidative phosphorylation . ATP is also synthesized by substrate level phosphorylation during glycolysis .ATP is synthesi...

Oswald Avery

...able to transfer genetic material through a liquid medium to other bacteria, transforming (giving new genetic characteristics) them. Therefore if bacteria transform when an organic molecule is placed in liquid with them, then that molecule holds genetic information. For the experiment, a bacteria called...

Magnetic resonance imaging

... study connections in the brain. In an isotropic medium (inside a glass of water for example) water molecules naturally move according to Brownian motion . In biological tissues however the diffusion is very often anisotropic . For example a molecule inside the axon of a neuron has a low probability t...

Monoclonal antibody

... certain conditions (namely in the presence of HAT medium ). Fusions between healthy B-cells and myeloma cells are rare, but when one succeeds, then the healthy partner supplies the needed enzyme and the fused cell can survive in HAT medium. This is the trick to detect the successfully fused cells. Appl...

Mathematical biology

..., biostatistics , cellular automata , excitable medium , Ewens's sampling formula , Lotka-Volterra equation , mathematical model , morphometrics , population dynamics , population genetics , theoretical biology . External links Society for Mathematical Biology European Society for Mathem...

Louis Pasteur

...t all particles from passing through to the growth medium and even in vessels with no filter at all, with air being admitted via a long tortuous tube that would not allow dust particles to pass. Nothing grew in the broths; therefore, the living organisms that grew in such broths came from outside, as spores...

Fermentation

...er to the bulk growth of microorganisms on some medium . No distinction is made between aerobic and anaerobic metabolism when the word is used in this sense. This process is often used to produce or preserve food. Fermentation typically refers to the fermentation of sugar to alcohol using ye...

Electrophysiology

...hnique an electrode is placed on the extracellular medium and field-potentials contributed by the action potentials of many neurons are recorded. Some popular clinical applications of extracellular recording are the electrocardiogram (ECG) and the electroencephalogram (EEG). 3. The patch-clamp techni...

Chromatography

...ffinities of substances for a gas or liquid mobile medium and for a stationary adsorbing medium through which they pass; such as paper , gelatin , or magnesium silicate gel. Analytical chroma...

Affinity chromatography

...lecules in solution, such as a cell lysate, growth medium or blood serum. The molecule of interest will have...geneous mixture will not become trapped. The solid medium can then be removed from the mixture, washed and the target molecule released from the entrapment in...

Albinism

... not completely absent (white) but shows a pale or medium blonde. Often the affected persons are paler in complexion as the rest of the family. The myth that all persons with albinism have "white hair and red eyes" is not true. Colorless iris in humans is pale blue, not pink like in some animals, and the ...