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