Biomaterial Database

MALDI ion trap mass spectrometer with charge detector for large biomolecule detection. 2010

Chien-Hsun Chen, and Jung-Lee Lin, and Ming-Lee Chu, and Chung-Hsuan Chen

Genomics Research Center, Academia Sinica, Taipei, Taiwan.

Up to now, all commercial matrix-assisted laser desorption/ionization (MALDI) mass spectrometers still can not efficiently analyze very large biomolecules. In this work, we report the development of a novel MALDI ion trap mass spectrometer which can enrich biomolecular ions to enhance the detection sensitivity. A charge detector was installed to measure the large ions directly. With this design, we report the first measurement of IgM with the mass-to-charge ratio (m/z) at 980 000. In addition, quantitative measurements of the number of ions can be obtained. A step function frequency scan was first developed to get a clear signal in the m/z range from 200,000 to 1,000,000.

UI	MeSH Term	Description	Entries
D007075	Immunoglobulin M	A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally was called a macroglobulin.	Gamma Globulin, 19S,IgM,IgM Antibody,IgM1,IgM2,19S Gamma Globulin,Antibody, IgM
D007477	Ions	An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D012680	Sensitivity and Specificity	Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)	Specificity,Sensitivity,Specificity and Sensitivity
D019032	Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization	A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.	Laser Desorption-Ionization Mass Spectrometry, Matrix-Assisted,MALD-MS,MALDI,Mass Spectrometry, Matrix-Assisted Laser Desorption-Ionization,Mass Spectroscopy, Matrix-Assisted Laser Desorption-Ionization,Matrix-Assisted Laser Desorption-Ionization Mass Spectrometry,Spectroscopy, Mass, Matrix-Assisted Laser Desorption-Ionization,MALDI-MS,MS-MALD,SELDI-TOF-MS,Surface Enhanced Laser Desorption Ionization Mass Spectrometry,Laser Desorption Ionization Mass Spectrometry, Matrix Assisted,MALDI MS,Mass Spectrometry, Matrix Assisted Laser Desorption Ionization,Mass Spectroscopy, Matrix Assisted Laser Desorption Ionization,Matrix Assisted Laser Desorption Ionization Mass Spectrometry