{HEAD ~ Detection} of an increase in fluorescent signal indicates {TAIL ~ the presence} of the enzyme in the sample 
indicates
{ HEAD ~ Detection } of an increase in fluorescent signal indicates { TAIL ~ the presence } of the enzyme in the sample
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH