The collection surface of {HEAD ~ the swab} thus maintains {TAIL ~ contact} with the rehydrated media plug 
The collection surface of { HEAD ~ the swab } thus maintains { TAIL ~ contact } with the rehydrated media plug
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH