Depending on how many targets or analytes are being measured:
#Usual assays are simple or single target assays which is usually the default unless it is called multiplex.
#Multiplex assays are used to simultaneously measure the presence, concentration, activity, or quality of multiple analytes in a single test. The advent of multiplexing enabled rapid, efficient sample testing in many fields, including immunology, cytochemistry, genetics/genomics, pharmacokinetics, and toxicology.