Patent ID: 7364843

Claim:
A method of identifying a target cell using a virus, the method comprising: infecting the target cell with the virus by contacting the virus to the target cell and culturing the target cell to propagate the virus; adding a chromogenic substrate to the resultant cell culture to induce enzyme reaction converting the chromogenic substrate to a chromogenic product; and measuring an optical signal emitted from the chromogenic product, wherein, when the optical signal is detected at a predetermined wavelength, it is determined that the target cell is present in the cell culture; wherein the virus contains in its genome a gene encoding an enzyme capable of converting the chromogenic substrate to the chromogenic product and a gene encoding a ligand allowing the virus to specifically bind with a receptor of the target cell to infect the target cell with the virus, wherein the enzyme is expressed in the form of a fusion protein at a virion surface, wherein the virus is a bacteriophage, and wherein the enzyme-encoding gene is a gene encoding an enzyme selected from the group consisting of peroxidase and alkaline phosphatase.