{HEAD ~ The fluid} containing {TAIL ~ the photosensitizer} may be flowed into a photopermeable container for irradiation 
containing
{ HEAD ~ The fluid } containing { TAIL ~ the photosensitizer } may be flowed into a photopermeable container for irradiation
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH