High-throughput and high-resolution two dimensional mapping of pI and m/z using a microchip in a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer.
We have developed a high-throughput, two-dimensional-mapping (isoelectric point [pI], mass-to-charge ratio [m/z]) method by combining a capillary isoelectric focusing chip sealed with removable resin tape and a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer. Sample proteins are separated in a meandering channel on the chip and immediately frozen. The tape is then removed and the proteins are freeze-dried. The freeze-drying maintains the separation state of the proteins and prevents movement of the sample solution, which can reduce pI resolution. A matrix solution is then applied and mass spectrometry is carried out by laser irradiation. The whole process takes less than 70 min, more than 10 times faster than with two-dimensional, polyacrylamide gel electrophoresis.
Fujita
Machiko
M
Fundamental and Environmental Research laboratories, NEC Corporation, Tsukuba, Ibaraki, Japan. m-fujita@frl.cl.nec.co.jp
Hattori
Wataru
W
Sano
Tohru
T
Baba
Masakazu
M
Someya
Hiroko
H
Miyazaki
Kenji
K
Kamijo
Ken'ichi
K
Takahashi
Katsutoshi
K
Kawaura
Hisao
H
D007525:Isoelectric Focusing; D007526:Isoelectric Point; D013050:Spectrometry, Fluorescence; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation*