Specificity means the ability of {HEAD ~ the membrane} to selectively bind or filter {TAIL ~ certain species} from complex mixtures 
to selectively bind
Specificity means the ability of { HEAD ~ the membrane } to selectively bind or filter { TAIL ~ certain species } from complex mixtures
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH