In {TAIL ~ preferred embodiments}, the serum samples are fractionated via {HEAD ~ anion exchange chromatography} 
In { TAIL ~ preferred embodiments } , the serum samples are fractionated via { HEAD ~ anion exchange chromatography }
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD