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.
Restriction enzymes (also known as restriction endonucleases) are proteins which cut DNA up at specific sequences in the genome. For example, the commonly used restriction end â¦ onuclease EcoRI recognizes every point in DNA with the sequence GAATTC, and cuts at the point between the Guanine and Adenine.