title: Use of octadecyl silica as an alternative non-conventional solid phase in immunoradiometric assays.
abstract: The use of chemically modified silica (octadecyl silica or Si-C18), a liquid chromatography stationary reverse phase, is proposed as an alternative solid phase for immunoradiometric assays (IRMAs). Si-C18 and polyvinylchloride solid phases were compared in their efficiency to detect a murine plasma protein (sex-limited protein or Slp) in a two site-two antibody IRMA. Si-C18 is at least as sensitive as PVC since Slp could be detected in plasmas diluted 1/128,000 and 1/64,000 respectively. The fact that 1 mg of Si-C18 can adsorb 5-14 times more protein than a PVC well is in agreement with the larger relative surface of Si-C18 beads (approximately 50 cm2/mg), compared with the PVC (approximately 1 cm2/well). These results strongly suggest that the Si-C18 matrix, saturated with specific antibodies, could be an exceptional probe to rescue and detect antigenic moieties diluted in large volumes of complex biological fluids.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universidad de Chile, Santiago.
authors.forename: S
authors.initials: S
authors.lastname: Lavandero
authors.forename: A
authors.initials: A
authors.lastname: Ferreira
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001798:Blood Proteins / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D003181:Complement C4 / Q000235:genetics; D005260:Female; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D011143:Polyvinyl Chloride; D011874:Radiometry; D012822:Silicon Dioxide; D013045:Species Specificity
chemical_list: D000911:Antibodies, Monoclonal; D001798:Blood Proteins; C018386:C4a protein, mouse; D003181:Complement C4; C026679:octadecylsilica; D012822:Silicon Dioxide; D011143:Polyvinyl Chloride