Polyvinyl alcohol-glutaraldehyde as solid-phase in ELISA for schistosomiasis

Preparaçöes antigenicas soluveis de Schistosoma mansoni adulto (SWAP) fixadas covalentemente em discos de polivinil alcool-glutaraldeido foram usadas em teste de ELISA. As melhores condiçöes para o ensaio foram estabelecidas e foi encontrado que uma quantidade mínima de antigeno, em torno de 1,5 ug e necessária. Comparaçäo entre este procedimento e o de ELISA convencional foi estabelecida. Um metodo seguro de imobilizaçäo do antigeno foi alcançado e os baixos preços dos reagentes empregados säo economicamente atraentes...

The use of dacron plates for DOT enzyme-linked immunosorbent assay (DOT-ELISA)

Dacron (polyethylenetherephthalate) is proposed as a matrix for dot-ELISA procedures, as an alternative to nitrocellulose. Plates of dacron were partially hydrazinolyzed and hydrazide groups introduced were converted to azide groups. The derivative dacron-antigen was covalently linked on to the plates through these azide groups. The derivative dacron-antigen was exaustively washed according to CROOK and antigen was still fixed onto the plates. Protein F1A purified from Yersinia pestis was used as a model. Triration of sera from immunized and non immunized rabbits against this protein was carried out by employing the dot-ELISA method. No significant difference was observed using dacron-antigen and nitrocellulose-antigen preparations. Howwvwe, both procedures showed to have a significant better performance in comparasion with the passive hemagglutination method. The specificity and reproductibility of the dot-ELISA assay using both preparations showed a similar behaviour. Nitrocellulose preparation was stable at 4 graus Centígrados, 28 graus centígrados and -20 graus centígrados for 90 days, whereas the dacron-antigen derivative was stable only when stored at 4 graus centígrados. Dacron-antigen derivative could be re-used when the spot developing was proceeded using 4-chloro-1-naphtol as substrate