Effect of non-ionic polymers on the formation of immuno-precipitates in single radial immunodiffusion techniques

Abstract

The effect of some non-ionic polymers on immunoprecipitin ring formation (in the assay of IgE in serum by simple radial immunodiffusion (SRD)) was investigated. Polymers were either added to the antigen well after the antigen and/or they were included together with the antibodies in the gel. A considerable enhancement of ring width was found when the low molecular weight polyethylene glycol, Carbowax 200, was added to the antigen well following antigen addition. On the other hand, incorporation of Carbowax 200 or other non-ionic polymers into the gel before antigen delivery caused a decrease in precipitin ring width. The presence of Carbowax 6000 in the gel improved the visualization of the precipitate although its presence slightly diminished the ring width of the precipitate.