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