We genetically engineered M13 bacteriophage, a long filamentous particle that forms liquid crystalline phases, and coupled biotin groups to one end of the virus. Biotinylated virus particles were then conjugated to streptavidin-coated polysterene spheres to form star complexes. The interparticle potential was measured between pairs of polystyrene beads grafted with phage particles using an optical tweezer, and their behaviour in nematic M13 virus suspensions was also studied.