For example, {HEAD ~ the control region} can contain a non diffusibly bound control reagent that is complementary to {TAIL ~ the diffusively bound labeled reagent} of the first region 
For example , { HEAD ~ the control region } can contain a non diffusibly bound control reagent that is complementary to { TAIL ~ the diffusively bound labeled reagent } of the first region
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH