The liquid reagent 17 is then squirted directly onto {TAIL ~ the portion} of {HEAD ~ the test pad} 12 bearing the first reagent 13 
The liquid reagent 17 is then squirted directly onto { TAIL ~ the portion } of { HEAD ~ the test pad } 12 bearing the first reagent 13
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH