[Dependence of the melting temperature of phage DNA on the GC pair content in a solvent with low ionic strength]

Base ratio of DNA from 21 bacteriophage of Pseudomonas was determined by chemical hydrolysis and paper chromatography. Obtained values of the GC pair content were compared with melting temperature of DNA in 0,1 X SSC. The content of GC pairs correlates with melting temperature by equation %GC = 2,53 (Tm - 53,4). The content of GC pair for DNA from 30 bacteriophages of Pseudomonas was calculated. Some speculations concerning the distribution in DNA base ratio of bacteriophages of Pseudomonas are discussed.