title: Porous silicon antibody microarrays for quantitative analysis: measurement of free and total PSA in clinical plasma samples.
abstract: The antibody microarrays have become widespread, but their use for quantitative analyses in clinical samples has not yet been established. We investigated an immunoassay based on nanoporous silicon antibody microarrays for quantification of total prostate-specific-antigen (PSA) in 80 clinical plasma samples, and provide quantitative data from a duplex microarray assay that simultaneously quantifies free and total PSA in plasma. To further develop the assay the porous silicon chips was placed into a standard 96-well microtiter plate for higher throughput analysis. The samples analyzed by this quantitative microarray were 80 plasma samples obtained from men undergoing clinical PSA testing (dynamic range: 0.14-44 ng/ml, LOD: 0.14 ng/ml). The second dataset, measuring free PSA (dynamic range: 0.40-74.9 ng/ml, LOD: 0.47 ng/ml) and total PSA (dynamic range: 0.87-295 ng/ml, LOD: 0.76 ng/ml), was also obtained from the clinical routine. The reference for the quantification was a commercially available assay, the ProStatus PSA Free/Total DELFIA. In an analysis of 80 plasma samples the microarray platform performs well across the range of total PSA levels. This assay might have the potential to substitute for the large-scale microtiter plate format in diagnostic applications. The duplex assay paves the way for a future quantitative multiplex assay, which analyzes several prostate cancer biomarkers simultaneously.
authors.affiliation: Dept. of Laboratory Medicine, Div. of Clinical Chemistry, Lund University, Skåne University Hospital, 205 02, Malmö, Sweden.|Dept. of Measurement Technology and Industrial Electrical Engineering, Div. Nanobiotechnology, Lund University, 223 63, Lund, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Järås
authors.affiliation: Dept. of Measurement Technology and Industrial Electrical Engineering, Div. Nanobiotechnology, Lund University, 223 63, Lund, Sweden.
authors.forename: Belinda
authors.initials: B
authors.lastname: Adler
authors.affiliation: Dept. of Measurement Technology and Industrial Electrical Engineering, Div. Nanobiotechnology, Lund University, 223 63, Lund, Sweden.
authors.forename: Axel
authors.initials: A
authors.lastname: Tojo
authors.affiliation: Dept. of Laboratory Medicine, Div. of Clinical Chemistry, Lund University, Skåne University Hospital, 205 02, Malmö, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Malm
authors.affiliation: Dept. of Measurement Technology and Industrial Electrical Engineering, Div. Nanobiotechnology, Lund University, 223 63, Lund, Sweden.
authors.forename: György
authors.initials: G
authors.lastname: Marko-Varga
authors.affiliation: Dept. of Laboratory Medicine, Div. of Clinical Chemistry, Lund University, Skåne University Hospital, 205 02, Malmö, Sweden.|Departments of Laboratory Medicine, Surgery, and Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.|Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom.
authors.forename: Hans
authors.initials: H
authors.lastname: Lilja
authors.affiliation: Dept. of Measurement Technology and Industrial Electrical Engineering, Div. Nanobiotechnology, Lund University, 223 63, Lund, Sweden.|Department of Biomedical Engineering, Dongguk University, Seoul, South Korea.
authors.forename: Thomas
authors.initials: T
authors.lastname: Laurell
mesh_terms: D000906:Antibodies / Q000737:chemistry* / Q000276:immunology; D000937:Antigen-Antibody Reactions; D005260:Female; D015200:Fluoroimmunoassay; D006801:Humans; D016062:Porosity; D017430:Prostate-Specific Antigen / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D040081:Protein Array Analysis; D012825:Silicon / Q000737:chemistry* / Q000276:immunology; D013499:Surface Properties
chemical_list: D000906:Antibodies; D017430:Prostate-Specific Antigen; D012825:Silicon