Purification of Streptomyces Venezuelae Phage

Kolstad, R. A. (University of Minnesota, Minneapolis), and S. G. Bradley. Purification of Streptomyces venezuelae phage. J. Bacteriol. 87:1157-1161. 1964.-Streptomyces venezuelae phage MSP8 was concentrated and purified by a combination of methods including dialysis against polyethylene glycol, partitioning between the two phases of aqueous polymer systems, gel filtration, chromatography on ECTEOLA-cellulose, and differential centrifugation. S. venezuelae phage MSP8 is 57% deoxyribonucleic acid and 43% protein. Its head is 55 by 70 mmu, and its tail is 10 by 150 mmu. Its dry weight is 250 mg per 10(15) plaqueforming units, and its density is 1.4. Phage MSP8 contains 15 mug of phosphorus and 40 mug of nitrogen per 10(12) particles. The ratio of light absorbancy at 260 to 280 mmu is 1.5. A mixture of two actinophages, MNP3 and MVP7, was separated by use of ECTEOLA-cellulose. In one fraction, 99% of the phage was MNP3; in another fraction, 99% of the phage was MVP7.