Reca-assisted cloning of dna

摘要

DNA is cloned and labeled in a sequence-specific manner. The DNA is digested with one or more restriction enzymes which produce 3' recessed ends. A desired fragment is protected from elongation by DNA polymerase by addition of E. coli RecA protein and oligonucleotides about 30 to 60 bases in length complementary to the 3' recessed ends of the digested fragment. RecA and DNA polymerase are then inactivated, leaving only the desired fragment with 3' recessed ends which is then ligated into a vector containing complementary 3' recessed ends.