Coliphage which requires either the LamB protein or the OmpC protein for adsorption to Escherichia coli K-12.

Either of two different proteins in the outer membrane of Escherichia coli K-12 (LamB and OmpC) can function in the constitution of receptor activity for a newly isolated T-even bacteriophage. This bacteriophage (SSI) differs from other T-even phages which use the OmpC protein as their receptors. The simple procedure used to isolate phage SSI may be suitable for the detection of bacteriophages with novel outer membrane receptor requirements.