Mass spectrometric analysis of nanoscale sample volumes extracted from open microchannels after sample preconcentration applied on amyloid beta peptides.
A new instrumental concept for extraction of nanovolumes from open microchannels (dimensions 150 μm × 50 μm, length 10 mm) manufactured on silicon microchips has been used in combination with a previously developed method for preconcentrating proteins and peptides in the open channels through electromigration. The extracted nanovolumes were further analyzed using nanoelectrospray ionization (nESI) or matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) directly or with subsequent enzymatic protein digestion in a nanodroplet prior to the MS analysis. Preconcentration of the samples resulted in a 15-fold sensitivity increase in nESI for a neurotensin solution, and using MALDI-MS, amyloid beta (Aβ) peptides could be detected in concentrations down to 1 nM. The method was also successfully applied for detection of cell culture Aβ.
Department of Chemistry, Division of Applied Physical Chemistry, Analytical Chemistry, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Teknikringen 36, 100 44, Stockholm, Sweden, saaram@kth.se.
Saara
S
Mikkonen
Johan
J
Jacksén
Åsa
Å
Emmer
D016229:Amyloid beta-Peptides / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D045744:Cell Line, Tumor; D006736:Horses; D006801:Humans; D046208:Microchip Analytical Procedures; D036103:Nanotechnology; D009496:Neurotensin / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors; D014867:Water / Q000737:chemistry
D016229:Amyloid beta-Peptides; D010455:Peptides; D011506:Proteins; D011994:Recombinant Proteins; D014867:Water; D009496:Neurotensin