The apparatus, when used with a centrifuge, allows for the creation of {HEAD ~ at least three fractions} in {TAIL ~ the apparatus} 
in
The apparatus , when used with a centrifuge , allows for the creation of { HEAD ~ at least three fractions } in { TAIL ~ the apparatus }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL