Reactions were terminated by {HEAD ~ rapid filtration} and {TAIL ~ the radioactivity} bound to the filters counted by liquid scintillation spectrophotometry 
Reactions were terminated by { HEAD ~ rapid filtration } and { TAIL ~ the radioactivity } bound to the filters counted by liquid scintillation spectrophotometry
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH