BioScience Dictionary

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Found Chromatography 21 times.

Displaying results 1 to 10.

1. Acetyl reduction assay (acetylene reduction assay)
A technique for measuring the nitrogen fixation activity in photosynthetic organisms. It uses a flame ionization detector and a gas chromatography apparatus to determine the reduction of acetylene to ethylene by the enzyme nitrogenase .

2. Affinity chromatography
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.

3. Anion exchange resin
A resin with fixed cationic groups which is used in chromatography to separate anionic molecules.

4. Bio-beads S
Polystyrene beads used to fractionate molecular compounds in gel filtration chromatography with lipophilic solvents.

5. Cation exhange resin
An insoluble resin with fixed anion ic groups which is used in chromatography to separate cation ic molecules.

6. Chromatography
An analytical technique used to separate molecules based on how they tend to cling to or dissolve in various solids, liquids and gases:* column chromatography is used most often to separate protein s based on their binding to a column lined with a ligand specific to a certain protein. * gel filtration chromatography is used most often to separate proteins by running the solution containing the proteins through a column filled with porous carbohydrate gel beads which will trap or slow down small molecules but will allow larger molecules to slide past. * paper chromatography separates molecules by taking advantage of their differing solubilities in a mix of solvents. The material to be separated is applied to a special piece of paper, and the edge of the paper is put in the solvent mix, which travels through the paper by capillary action and carries the different molecules at different rates with it.

7. Concanavalin A (con A)
A protein found in the jack beans plant Canavalin ensiformis which sticks various cell types and glycoprotein s (proteins with sugar s attached) to one another by crosslinking them. It can also function much like platelet s in blood do for animals. Also, it encourages mitosis and cell division in dormant lymphocyte s. It is used in the lab technique of affinity chromatography to purify glycoproteins.

8. Cyanogen bromide (CNBr)
An inorganic, toxic substance with the chemical formula CNBr which is white and crystalline with a sharp odor, is an irritant, and can be dissolved in water, alcohol , and ether. It melts at 52 degrees Celsius and boils at 61.4 degrees Celsius. It is used to extract gold, in pesticide s, and in the chemical synthesis of organic substances. It is also used in genetic engineering to cleave polypeptide chains, especially synthetic protein s, wherever the amino acid methionine occurs. It is also used to attach protein ligand s to various supporting substances in preparation for affinity chromatography .

9. Eluant
The term for the fluid (such as a buffer solution) that is used in column chromatography to separate the components of a mixed sample. The fluid is run through the column and brings out the separated substances (separately). Also see elution .

10. Eluate
The waste liquid produced during chromatography .