{HEAD ~ Certain reducible compounds} are useful in {TAIL ~ analytical compositions}, elements and methods, e.g. for assays of bacterial cells 
are useful in
{ HEAD ~ Certain reducible compounds } are useful in { TAIL ~ analytical compositions } , elements and methods , e.g. for assays of bacterial cells
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH