Direct from Polyacrylamide Gel Infrared Laser Desorption/Ionization
The direct combination of gel electrophoresis and infrared laser desorption/ionization time-of-flight mass spectrometry has been demonstrated. We present results for infrared laser desorption and ionization mass spectrometry of peptides and proteins directly from a polyacrylamide gel without the addition of a matrix. Analyte molecules up to 6 kDa were ionized directly from a vacuum-dried sodium dodecyl sulfate-polyacrylamide gel after electrophoretic separation. Mass spectra were obtained at the wavelength of 2. 94 μm, which is consistent with IR absorption by N-H and O-H stretch vibrations of water and other constituents of the gel. A 5-nmol quantity of peptide or protein was loaded per gel slot, although it was possible to obtain mass spectra from a small fraction of the gel spot. This technique shows promise for the direct identification of both parent and fragment masses of proteins contained in polyacrylamide gels.
Publication Source (Journal or Book title)
Xu, Y., Little, M., Rousell, D., Laboy, J., & Murray, K. (2004). Direct from Polyacrylamide Gel Infrared Laser Desorption/Ionization. Analytical Chemistry, 76 (4), 1078-1082. https://doi.org/10.1021/ac034879n