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