Abuur nooc ka mid ah weedhan ka sii adag Ka dib markii ay soo duulaan xarigga, DNA polymerase waxay kordhisaa dhamaadka xarigga 3'ee soo duulaya iyadoo la isku darayo DNA cusub.
Dabcan, qaab kale oo adag oo weedhan ah waa "Ka dib markii uu xadhkaha soo galo, DNA polymerase-ku wuxuu kordhiyaa xadhkaha 3' xadhkaha soo gala, isagoo u beddelaya D-loop qaab dhismeed iskutallaab ah oo loo yaqaan Holliday junction. "