a valve seating portion having a valve opening therein, said valve opening permitting {TAIL ~ serum} or plasma to flow into said tubular member when {HEAD ~ the separator tube} is plunged into the collection tube, 
a valve seating portion having a valve opening therein , said valve opening permitting { TAIL ~ serum } or plasma to flow into said tubular member when { HEAD ~ the separator tube } is plunged into the collection tube ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH