It is a further object of the invention to provide an assay vehicle suitable for use in {HEAD ~ an animal litter} or {TAIL ~ bedding} 
It is a further object of the invention to provide an assay vehicle suitable for use in { HEAD ~ an animal litter } or { TAIL ~ bedding }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL