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

Abstract

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. Titration 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. However, both procedures showed to have a significant better performance in comparison 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 degrees C, 28 degrees C and -20 degrees C for 90 days, whereas the dacron-antigen derivative was stable only when stored at 4 degrees C. Dacron-antigen derivative could be re-used when the spot developing was proceeded using 4-chloro-1-naphtol as substrate.

Dot enzyme-linked immunosorbent assay (dot-ELISA) for schistosomiasis diagnosis using dacron as solid-phase

“…We have no explanation for the positive reaction of sera from malaria patients; we do not know whether they had ever been in an endemic area for schistosomiasis. On the other hand, it is well known that, cross reaction between Schistosoma and filaria antigens can be observed regularly in ELISA 14 .…”

“…The plates and filters were washed five times as described before. The development of the spot was perfomed according to Montenegro et al (1991) 14 .…”

The use of filter paper plasticized with polyvinyl alcohol-glutaraldehyde in ELISA

“…Modern approaches have been reported such as the use of a fiber optic biosensor (8,9) and a PCR-based procedure (10). In our laboratories, different methods for the serologic diagnosis of this pathology have been proposed (10)(11)(12)(13)(14). Dacron plates and polyvinyl alcohol-glutaraldehyde discs have been used in these procedures.…”

The use of polyvinyl alcohol glutaraldehyde antigen coated discs for laser induced fluorescence detection of plague

“…Therefore, the laboratorial diagnosis is one of the concerned issues being evaluated (Almeida & Ferreira 1992). In our laboratories, a dot enzyme linked immunosorbent assay (dot-ELISA) has been previously proposed to detect specific antibodies in rabbits sera immunized against F1 protein obtained from Y. pestis by using a new solid phase -Dacron® (Montenegro et al 1991(Montenegro et al , 1993. Furthermore, ferromagnetic Dacron was also suggested as solid phase in enzyme immunodiagnosis (Carneiro Leão et al 1994).…”