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