In clinical terms, a
potentiator is a
reagent that enhances sensitization of an
antigen. Potentiators are used in the clinical laboratory for performing
blood banking procedures that require enhancement of
Agglutination (biology) to detect the presence of antibodies or antigens in a patient's blood sample. Examples of potentiators include
albumin, LISS (low ionic-strength saline) and PEG (
polyethylene glycol). Potentiators are also known as enhancement reagents. Albumin acts as a potentiator by reducing the
zeta potential around the suspended red blood cells, thus dispersing the repulsive negative charges and enhancing agglutination.
Low
ionic
strength
saline is a potentiator that acts by not only reducing the
zeta potential, but also by increasing the amount of antibody taken up by the red blood cell during sensitization. LISS is a solution of
glycine and albumin.
Poly
ethylene
glycol 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 37 °C incubation. PEG is not appropriate for use in samples from patients with increased plasma protein, such as patients with
multiple myeloma. False-positive results may occur more frequently with the use of polyethylene glycol due to its strong agglutination capabilities.