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