Preferably, {HEAD ~ the concentration} of the dendron in the solution is {TAIL ~ approximately 1 mM} or more 
is
Preferably , { HEAD ~ the concentration } of the dendron in the solution is { TAIL ~ approximately 1 mM } or more
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH