The heating elements are pulsed by an electrical circuit at a rate substantially faster than the rate of {HEAD ~ introduction} of {TAIL ~ new assay cartridges} 
of
The heating elements are pulsed by an electrical circuit at a rate substantially faster than the rate of { HEAD ~ introduction } of { TAIL ~ new assay cartridges }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL