recombined

Recombined is the past tense and past participle of recombine, meaning to join together again or to form a new combination from previously separated parts. The term is used across sciences and engineering to describe processes in which components are brought back into a combined state or results that arise from such processes.

In genetics and molecular biology, recombination describes the exchange or rearrangement of genetic material. Recombined DNA refers to DNA fragments that have been spliced together to form a new sequence, often using restriction enzymes or recombinases. Recombinant DNA technology enables expression of foreign genes and production of recombinant proteins.

In chemistry, recombination refers to reactions in which two or more species—often radicals or ions—combine to form a single product. Radical recombination is common in combustion and atmospheric chemistry; ion recombination occurs in plasmas or radiolysis, yielding neutral molecules.

In physics and astronomy, recombination is a key process in plasmas and the early universe. Electron–ion recombination reduces free electrons, emitting photons. The recombination epoch marks the time when free electrons combined with protons to form neutral hydrogen, allowing photons to travel freely and producing the cosmic microwave background.

In semiconductor physics, electron–hole recombination describes how excited charge carriers annihilate, emitting light in LEDs and lasers or wasting energy as heat in other devices. The rate of recombination affects device efficiency and performance.