The apparatus 5, comprising {HEAD ~ an automated optical observation system} for detecting and enumerating {TAIL ~ the immobilized entities} 
for enumerating
The apparatus 5 , comprising { HEAD ~ an automated optical observation system } for detecting and enumerating { TAIL ~ the immobilized entities }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL