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