title: Element-tagged immunoassay with ICP-MS detection: evaluation and comparison to conventional immunoassays.
abstract: We have investigated the possibility of using element-tagged antibodies for protein detection and quantification in microplate format using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and compared the results to conventional immunoassays, such as Enzyme-Linked Immunosorbent Assay (ELISA) and Western blotting. The technique was further employed to detect low levels and measure DNA-binding activity of transcription factor p53 in leukemia cell lysates through its interaction with immobilized oligonucleotides and recognition by element-tagged antibodies. The advantages of ICP-MS detection for routine performance of immunoassays include increased sensitivity, wide dynamic range, minimal interference from complex matrices, and high throughput. Our approach advances the ICP-MS technology and demonstrates its applicability to proteomic studies through the use of antibodies directly labeled with polymer tags bearing multiple atoms of lanthanides. Development of this novel methodology will enable fast and quantitative identification of multiple analytes in a single well.
authors.affiliation: Chemistry Department, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6.
authors.forename: Eva
authors.initials: E
authors.lastname: Razumienko
authors.forename: Olga
authors.initials: O
authors.lastname: Ornatsky
authors.forename: Robert
authors.initials: R
authors.lastname: Kinach
authors.forename: Michael
authors.initials: M
authors.lastname: Milyavsky
authors.forename: Eric
authors.initials: E
authors.lastname: Lechman
authors.forename: Vladimir
authors.initials: V
authors.lastname: Baranov
authors.forename: Mitchell A
authors.initials: MA
authors.lastname: Winnik
authors.forename: Scott D
authors.initials: SD
authors.lastname: Tanner
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry*; D015153:Blotting, Western; D004247:DNA / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D020014:K562 Cells; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D010982:Platelet-Derived Growth Factor / Q000032:analysis; D016159:Tumor Suppressor Protein p53 / Q000032:analysis / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D028581:Lanthanoid Series Elements; D010982:Platelet-Derived Growth Factor; D016159:Tumor Suppressor Protein p53; C075278:platelet-derived growth factor A; D004247:DNA