The isolation of phage particles possessing an extremely high activity

Summary

Coli-phage protein samples possessing extremely high activity could be isolated by our isoelectric precipitation method from culture filtrates of high titres, which had been prepared by a method described in this paper.

The minimal dosis of the most active sample for producing a plaque on agar plate was 6,8×10⁻¹⁶ g. Since the dry weight of a single phage particle is considered to be about 1/2×10⁻¹⁵ g., almost every protein particle of such a sample would be able to produce the plaque.

No difference was found in their physical and chemical properties between such highly active phage particles and lipoprotein particles possessing no phage activity, isolated from normal cells of B. coli.