a) placing an aliquot of sample onto {HEAD ~ a test element comprising}, in overlying {TAIL ~ relation}, 
a ) placing an aliquot of sample onto { HEAD ~ a test element comprising } , in overlying { TAIL ~ relation } ,
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL OTH