title: Direct antigen detection from immunoprecipitated beads using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; a new method for immunobeads-mass spectrometry (iMS).
abstract: One-step detection of biological molecules is one of the principal techniques for clinical diagnosis, and the potential of mass spectrometry for biomarker detection has been a promising new approach in the field of medical sciences. We demonstrate here a new and high-sensitivity method that we termed immunobeads-mass spectrometry (iMS), which combines conventional immunoprecipitation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The key feature of iMS is the MS-compatible condition of immunoprecipitation using detergents with a monosaccaride-C8 alkyl chain or a disaccharide-C10 alkyl chain, and the minimized number of steps required for high-sensitivity detection of target peptides in serum or biological fluid. This was achieved by optimizing the wash buffer and subjecting the immunobeads directly to MALDI-TOF MS analysis. Using this method, we showed that 1 fmol of amyloid beta peptide spiked in serum was readily detectable, demonstrating the powerful tool of iMS as a biomarker detection method.
authors.affiliation: Life Science Research Center, Shimadzu Corporation, Kanda-Nishikicho 1, Tokyo 101-8448, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimada
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Toyama
authors.forename: Chikage
authors.initials: C
authors.lastname: Aoki
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Aoki
authors.forename: Koichi
authors.initials: K
authors.lastname: Tanaka
authors.forename: Taka-Aki
authors.initials: TA
authors.lastname: Sato
mesh_terms: D016229:Amyloid beta-Peptides / Q000097:blood; D000941:Antigens / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D003902:Detergents / Q000737:chemistry; D006801:Humans; D047468:Immunoprecipitation / Q000379:methods*; D057230:Limit of Detection; D008863:Microspheres; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D016229:Amyloid beta-Peptides; D000941:Antigens; D015415:Biomarkers; D003902:Detergents