{HEAD ~ The biomolecules} can be labeled with the dyes either directly or indirectly through {TAIL ~ a phosphoramidite} 
labeled indirectly through
{ HEAD ~ The biomolecules } can be labeled with the dyes either directly or indirectly through { TAIL ~ a phosphoramidite }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL