Consideration of that question raises issues of complement fixation and the like, which then drives the selection of the particular class or {HEAD ~ isotype} of {TAIL ~ antibody} 
of
Consideration of that question raises issues of complement fixation and the like , which then drives the selection of the particular class or { HEAD ~ isotype } of { TAIL ~ antibody }
OTH OTH OTH OTH OTH 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