DNA for cloning experiments may also be obtained from RNA using reverse transcriptase (complementary DNA or cDNA cloning), or in the form of synthetic DNA (artificial gene synthesis).
DNA potem očistimo z uporabo preprostih metod za odstranjevanje proteinov (ekstrakcija s fenolom), RNA (razgradnja z ribonukleazami) in majhnih molekul (obarjanje in/ali kromatografija).