This further aids in {HEAD ~ the separation} of {TAIL ~ contaminants} and improves the performance of the assay 
of
This further aids in { HEAD ~ the separation } of { TAIL ~ contaminants } and improves the performance of the assay
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH