title: Rapid, low-technology field- and laboratory-applicable enzyme-linked immunosorbent assays for immunodiagnosis of Schistosoma mansoni.
abstract: Simple and rapid polystyrene- and nitrocellulose-based enzyme-linked immunosorbent assays were developed for detecting antibodies against adult Schistosoma mansoni microsomal antigens. The polystyrene test uses the Nunc Immuno Stick System. A single dilution of the antibody source being tested, the conjugate, and the substrate (3,3',5,5'-tetramethylbenzidine) are placed in tubes. Dried, antigen-coated polystyrene sticks are then exposed to the reagents by immersion. Once the sticks are sensitized, an entire assay can be completed in 8 min. Positive reactions result in a rich blue color in the substrate tube and can be distinguished with the naked eye. In the nitrocellulose-based test, a nitrocellulose sheet with antigen drawn in a line by pen is cut to produce identical strips. The ligand-binding steps and washings are performed in the troughs of incubation trays. The exposure times required for a single dilution of the antibody source being tested, the conjugate, and the substrate (3,3'-diaminobenzidine) are 5 min, 5 min, and 7.5 min, respectively. Once sensitized strips are available, an entire assay can be run in 50 min. Both techniques can assay serum or whole blood. The characteristics of polystyrene- and nitrocellulose-based techniques allow them to be used successfully in field studies and in minimally equipped laboratories.
authors.affiliation: Department of Clinical Pathology, Faculty of Medical Sciences, State University of Campinas, São Paulo, Brazil.
authors.forename: C L
authors.initials: CL
authors.lastname: Rossi
authors.forename: V C
authors.initials: VC
authors.lastname: Tsang
authors.forename: J B
authors.initials: JB
authors.lastname: Pilcher
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000947:Antigens, Helminth; D003101:Collodion; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005069:Evaluation Studies as Topic; D006801:Humans; D008861:Microsomes / Q000276:immunology; D011137:Polystyrenes; D012550:Schistosoma mansoni / Q000276:immunology; D012555:Schistosomiasis mansoni / Q000175:diagnosis* / Q000276:immunology
chemical_list: D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D011137:Polystyrenes; D003101:Collodion