Isoamyl alcohol
Isoamyl alcohol is a colorless liquid with the formula 2CHCH2CH2OH. It is one of several isomers of amyl alcohol. It is an ingredient in the production of banana oil, an ester found in nature and also produced as a flavouring in industry. It is a common fusel alcohol, produced as a major by-product of ethanol fermentation. It is also an ingredient of Kovac's reagent, used for the bacterial diagnostic indole test.
It is also used as an antifoaming agent in the chloroform isoamyl alcohol reagent.
Isoamyl alcohol is used in a phenol–chloroform extraction mixed with the chloroform to further inhibit RNase activity and prevent solubility of RNAs with long tracts of poly-adenine.
It is one of the components of the aroma of Tuber melanosporum, the black truffle. It has been identified as a chemical in the pheromone used by hornets to attract other members of the hive to attack.