Chrom-ELISA: A new technique for rapid identification of arboviruses

Abstract

The enzyme-linked immunosorbent assay (ELISA) technique was modified to enable rapid identification of arboviruses isolated by inoculation of newborn mice. Red Oil O was added to the brain suspension, which was purified by chromatography in agarose gel filtration. The viral antigen thus obtained was used to coat polystyrene microtitration plates and was tested against a battery of hyperimmune ascitic fluids used at their optimal dilution. The reaction was carried out by adding sheep anti-mouse IgG labelled with horseradish peroxidase and orthotolidine chromogenic substrate. The sensitivity and specificity of the method were tested with different arboviruses. This technique is rapid and identification is carried out in less than 4 h; it has a sensitivity threshold of 103.5LD50 and is simple and economical to use. Un test ELISA “optimisé” est décrit pour l'identification rapide des arbovirus isolés sur souriceaux nouveau-nés. L'extrait de cerveau préala-blement coloré par le “Red Oil O” est purifié par chromatographie en filtration sur gel d'agarose. Cet antigène viral est testé en microplaques de polystyrène contre différentes ascites hyperimmunes à leur dilution optimale, puis révélé au moyen d'un conjugué marqué par la peroxydase et d'un substrat chromogène à base d'orthotolidine. Cette technique est rapide (identification en moins de 4 h) et sensible (détection à partir de 103,5DL50); elle est aussi simple et économique.