{HEAD ~ The amount} of reducing substance and {TAIL ~ the period} of time for interaction are so adapted to obtain the product desired, whereafter the blood and plasma, respectively, are optionally fractionated in a known manner 
of reducing
{ HEAD ~ The amount } of reducing substance and { TAIL ~ the period } of time for interaction are so adapted to obtain the product desired , whereafter the blood and plasma , respectively , are optionally fractionated in a known manner
HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH