title: Protein biomarker enrichment by biomarker antibody complex elution for immunoassay biosensing.
abstract: It is very challenging to perform sample enrichment for protein biomarkers because proteins can easily change conformation and denature. In this paper we demonstrate protein enrichment suited for high-sensitivity integrated immuno-biosensing. The method enhances the concentration of the biomarkers and simultaneously removes matrix components that could interfere with the immunoassay. Biomarkers are captured using antibody coated magnetic particles and the biomarker antibody complexes are released by enzymatic elution. The eluted complexes are subsequently detected in a sandwich immunoassay biosensor. A scaling study of the enrichment process demonstrates an enrichment factor of 15 in buffer and plasma. We analyze the enrichment factor in terms of the three basic steps of the assay (capture, concentration, elution) and we quantify their respective efficiencies. The process is suited for integration into bio-analytical tools.
authors.affiliation: Philips Research, High Tech Campus 11, 5656 AE Eindhoven, The Netherlands.
authors.forename: Gwenola
authors.initials: G
authors.lastname: Sabatte
authors.forename: Harma
authors.initials: H
authors.lastname: Feitsma
authors.forename: Toon H
authors.initials: TH
authors.lastname: Evers
authors.forename: Menno W J
authors.initials: MW
authors.lastname: Prins
mesh_terms: D000936:Antigen-Antibody Complex / Q000302:isolation & purification; D015415:Biomarkers / Q000032:analysis; D014408:Biomarkers, Tumor / Q000097:blood; D015374:Biosensing Techniques / Q000379:methods*; D000939:Epitopes / Q000302:isolation & purification; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008280:Magnetics; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis; D011506:Proteins / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D000936:Antigen-Antibody Complex; D015415:Biomarkers; D014408:Biomarkers, Tumor; D000939:Epitopes; D011506:Proteins; D017430:Prostate-Specific Antigen