In particular, sulfonated aminocoumarins that are useful as fluorescent tracing agents and enzyme substrates, reactive derivatives of {HEAD ~ sulfonated aminocoumarins} useful as {TAIL ~ labels}, and their conjugates 
useful as
In particular , sulfonated aminocoumarins that are useful as fluorescent tracing agents and enzyme substrates , reactive derivatives of { HEAD ~ sulfonated aminocoumarins } useful as { TAIL ~ labels } , and their conjugates
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH