In a preferred embodiment the reducing agent is added to {HEAD ~ blood}, which preferably contains {TAIL ~ an anti coagulating agent}, such as trisodium citrate or directly to plasma 
preferably contains
In a preferred embodiment the reducing agent is added to { HEAD ~ blood } , which preferably contains { TAIL ~ an anti coagulating agent } , such as trisodium citrate or directly to plasma
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH