A concatemer is a long continuous DNA molecule that contains multiple copies of the same DNA sequences linked in series. These polymeric molecules are usually copies of an entire genome linked end to end and separated by cos sites (a protein binding nucleotide sequence that occurs once in each copy of the genome). Concatemers are frequently the result of rolling circle replication, and may be seen in the late stage of bacterial infection by phages. As an example, if the genes in the phage DNA are arranged ABC, then in a concatemer the genes would be ABCABCABCABC and so on.They are further broken by ribozymes.