Rapid detection of toxoplasmic nucleic acid by enzyme-linked immunofiltration-assay after membrane transfer

We report the use of enzyme-linked immunofiltration-assay (ELIFA) for rapid detection of Toxoplasma gondii DNA after transfer to nitrocellulose or nylon membranes. Saturation, specific labeling with a nonradioactive oligonucleotide probe and washing steps are included in an active filtration process, which is controled by microcomputer regulating reagent flow. This method provides excellent specificity, reproducibility and repeatability. Recycling in a closed circuit or by reversing the direction of flow provides the advantage of reducing the required volume of costly reagents (e.g. probes). ELIFA does not require lengthy membrane manipulation, and hybridization as well as stringency and revelation steps can be automated. The procedure can be carried out in less than 2 h, which is a major time saving compared to conventional solid-phase molecular hybridization techniques.