title: A new end-point for ELISA titrations.
abstract: This report describes a new ELISA procedure based on end-point titrations. This end-point ELISA takes advantage of the change of color intensity that occurs when peroxidase-containing wells of an ELISA plate are revealed with diaminobenzidine-nickel and further intensification with silver: as antibody concentration and, therefore, peroxidase concentration, decreased, the color became stronger in some wells and, afterwards (i.e., at lower antibody and peroxidase concentrations), the color faded toward clear background. It is proposed that the reciprocal of the sample dilution at which the color intensifies can be used as a measure of the sample antibody content. This report verifies the validity and precision of that procedure.
authors.affiliation: Departamento de Personalidad, Facultad de Psicología, Universidad de Barcelona, Barcelona, Spain. jvidal@ub.edu
authors.forename: José
authors.initials: J
authors.lastname: Vidal
mesh_terms: D015100:3,3'-Diaminobenzidine / Q000737:chemistry; D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D006801:Humans; D005779:Immunodiffusion / Q000379:methods; D007074:Immunoglobulin G / Q000032:analysis / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000032:analysis / Q000097:blood / Q000276:immunology; D007136:Immunoglobulins / Q000032:analysis*; D036341:Intercellular Signaling Peptides and Proteins; D051379:Mice; D009532:Nickel / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D009195:Peroxidase / Q000737:chemistry; D051381:Rats; D020318:Rats, Long-Evans; D015203:Reproducibility of Results; D012834:Silver / Q000737:chemistry; D017186:Titrimetry / Q000379:methods; D014611:Vaccination
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D015100:3,3'-Diaminobenzidine; D012834:Silver; C028310:poly-L-lysylphenylalanine; D009532:Nickel; D009195:Peroxidase