title: Infectivity of phage P2 DNA in presence of helper phage.
mesh_terms: D002499:Centrifugation, Density Gradient; D003090:Coliphages; D004279:DNA, Viral; D004926:Escherichia coli; D005827:Genetics, Microbial; D006378:Helper Viruses; D007700:Kinetics; D008970:Molecular Weight
chemical_list: D004279:DNA, Viral