sentences:  Before annealing can occur, one of the strands may need to be phosphorylated by an enzyme such as kinase to allow proper hydrogen bonding to occur.The term annealing is often used to describe the binding of a DNA probe, or the binding of a primer to a DNA strand during a polymerase chain reaction.The term is also often used to describe the reformation (renaturation) of reverse-complementary strands that were separated by heat (thermally denatured).