text: PAC is one of the artificial chromosome vectors. Some other artificial chromosomes include: bacterial artificial chromosome, yeast artificial chromosome and the human artificial chromosome. Compared to other artificial chromosomes, it can carry relatively large DNA fragments, however less so than the yeast artificial chromosome(YAC). Some advantages of PACs compared to YACs includes easier manipulation of bacteria system, easier separation from DNA hosts, higher transformation rate, more stable inserts, and they are non-chimeric which means they do not rearrange and ligate to form new DNA strand, allowing for a user friendly vector choice.