Ohio State University of Columbus, Ohio, has received US Patent No. 8,075,854, "Microfluidic chips for rapid multiplex ELISA. "The patent claims a microfluidic chip that consists of a substrate and a channel or multiple channels in the substrate. Each channel includes a tortuous path section or multiple tortuous path sections, according to the patent. A receptor for the detection of an analyte can be immobilized in a tortuous path section, for example by adsorption.