A rapid and semiquantitative lateral flow assay has been developed for detection of cephalexin (CFX) in milk. The assay is based on a competitive format using polyclonal antibodies. Antibodies were raised in rabbits against CFX-keyhole limpet hemocyanin. The specificity of antibodies was ascertained by direct enzyme-linked immunosorbent assay. The laboratory prepared gold nanoparticles coupled…