Completar frases Cleaving and rejoining DNAVersión en línea restriction enzymes serve as knives for genetic surgery por relax spot 1 fragments collection one purified many knives restriction enzymes serve as for genetic surgery . Hundreds of restriction enzymes with different recognition sequences have been from various organisms , so the knives come in forms . DNA cut with restriction enzymes creates a of all within a microcentrifuge tube . Typically we want only of the fragments .