P Bacteriophage Artificial Chromosomes, also known as PBACs, are essential tools in molecular biology research. PBACs are synthetic DNA molecules derived from bacteriophages, which are viruses that infect bacteria. These artificial chromosomes serve as vehicles to clone and propagate large genomic fragments in host bacterial cells. PBACs have become valuable in various applications, such as the construction of genomic libraries, the study of gene expression, and the development of genetically modified organisms. Synonyms for PBACs include bacteriophage-based artificial chromosomes, phage artificial chromosomes, and viral artificial chromosomes. These terms all refer to the same technology and highlight the incorporation of bacteriophage-derived elements in the construction of artificial chromosomes for genetic research.