{TAIL ~ The antibody coated beads} may be placed in a gradient fashion such that each layer binds to and selects {HEAD ~ a subset} of cells from the entire sample population 
{ TAIL ~ The antibody coated beads } may be placed in a gradient fashion such that each layer binds to and selects { HEAD ~ a subset } of cells from the entire sample population
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH