In {TAIL ~ the immunoassay}, {HEAD ~ a sample} containing antigen or antibody to be determined is mixed with the reagent composition 
In
In { TAIL ~ the immunoassay } , { HEAD ~ a sample } containing antigen or antibody to be determined is mixed with the reagent composition
REL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH