RUBELLA IGG DETECTION USING A SILVER-ENHANCED GOLD TECHNIQUE

Rubella IgG screening in the U.K. traditionally uses the single radial haemolysis (SRH) method or ELISA. Latex agglutination is used either for confirmation of a negative result or occasionally as a primary screening test. The drawbacks of the SRH test have prompted virologists to look for alternatives. A total of 823 sera were treated by the conventional SRH test and a silver-enhanced gold (SEG) assay. Eighty-two sera were further tested by two commercial latex (LA) tests. SEG for rubella was shown not to work with heat treated sera. Taking SRH as the 'gold' standard SEG gave a sensitivity of 94·4% and 97·4% specificity (uncorrected data). One serum would have been incorrectly reported by SRH as > 15 iu if the SEG and subsequent LA < 3 iu result had not been available. Seven other sera gave non-specific zones on the SRH control plates. The silver-enhanced gold technique described here in an optimized assay provides a possible alternative for large scale screening for rubella IgG. © 1990.