Nucleic acid thermodynamics of base incompatibility by quantifying the temperature at which two strands anneal can provide information as to the similarity in base sequence between the two strands being annealed. The complexes may be dissociated by thermal denaturation, also referred to as melting. In the absence of external negative factors, the processes of hybridization and melting may be repeated in succession indefinitely, which lays the ground for polymerase chain reaction. Most commonly, the pairs of nucleic bases A=T and G≡C are formed, of which the latter is more stable. DNA denaturation, also called DNA melting, is the process by which double-stranded deoxyribonucleic
Petroselinic acid in Garryaceae. In Picramniaceae, petroselinic acid is accompanied by tariric acid. In addition, petroselinic acid has been found in minor amounts in several fats of plant and animal origin, including in human sources. The occurrence of petroselinic acid as the major fatty acid is used in chemosystematics as a proof of a close relationship of several families within the Apiales as well as within the Garryales. Besides petroselinic acid, oleic acid has been shown to be present in all cases examined. Fatty acids mostly occur as their esters, commonly the triglycerides, which are the greasy materials in many natural oils.