Polyethylene glycol (PEG) in a LISS solution removes water from the system and thus concentrates the antibodies present. PEG can cause non-specific aggregation of cells, thus eliminating the necessity for centrifugation after  incubation.
The use of polyethylene glycol (PEG) in a LISS solution enables the removal of water from the system, thereby concentrating the antibodies. Additionally, PEG can induce non-specific cell clumping, rendering centrifugation unnecessary following incubation.