To achieve efficient signal generation, the invention can exploit {HEAD ~ either the intrinsic optical properties} of the microcolonies or {TAIL ~ various externally applied labeling reagents} 
of
To achieve efficient signal generation , the invention can exploit { HEAD ~ either the intrinsic optical properties } of the microcolonies or { TAIL ~ various externally applied labeling reagents }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL