Triggers of nonallergic rhinitis symptoms vary and can include certain odors or irritants in the air, changes in the weather, some medications, certain foods, and chronic health conditions. A diagnosis of nonallergic rhinitis is made after an allergic cause is ruled out.
DNA extraction. For the various methods, see Nucleic acid methods. DNA isolation is a process of purification of DNA from sample using a combination of physical and chemical methods. The first isolation of DNA was done in 1869 by Friedrich Miescher. Currently it is a routine procedure in molecular biology or forensic analyses.
Gel extraction. In molecular biology, gel extraction or gel isolation is a technique used to isolate a desired fragment of intact DNA from an agarose gel following agarose gel electrophoresis. After extraction, fragments of interest can be mixed, precipitated, and enzymatically ligated together in several simple steps. This process, usually performed on plasmids, is the basis for rudimentary genetic engineering. After DNA samples are run on an agarose gel, extraction involves four basic steps: identifying the f