Patent ID: 6858384

Claim:
A method for obtaining a phage particle comprising an antibody fragment directed against an antigen associated with the surface of target cells in a heterogeneous cell population, wherein said heterogeneous cell population comprises non-target cells and target cells in a heterogeneous mixture, and wherein said non-target cells and/or target cells are detectably labeled, the method comprising: (a) providing a library of phage particles that express antibody fragments on the surface of the phage particles; (b) incubating said library of phage particles with said heterogeneous cell population under conditions that allow binding of the antibody fragment expressed on the surface of the phage particles to said antigen associated with said target cells; (c) separating said target cells and phage particles bound therewith from phage particles not bound to said target cells; and (d) recovering the phage particles bound to the target cells.