Matrix-assisted laser desorption/ionization analysis

Alfonso, C. Fenselau, C. Use of bioactive glass shdes for matrix-assisted laser desorption/ionization analysis Apphcation to microorganisms. Anal. Chem. 2003, 75, 694-697. 

Donegan, M. Tomlinson, A. J. Nair, H. Juhasz, P. Controlling matrix suppression for matrix-assisted laser desorption/ionization analysis of... 

Bolbach, G. (2005) Matrix-assisted laser desorption/ionization analysis of non-covalent complexes fundamentals and applications. Curr. Pharm. Des., 11, 2535-57. 

C. M. Bentzley, M. V. Johnston, and B. S. Larsen, Base specificity of oligonucleotide digestion by calf spleen phosphodiesterase with matrix-assisted laser desorption ionization analysis, AwaZ. Biochem. 258, 31-37 (1998). 

Cvacka, J. and Svatos, A. (2003) Matrix-assisted laser desorption/ ionization analysis of lipids and high molecular weight hydrocarbons with lithium 2,5-dihydroxybenzoate matrix. Rapid Commun. Mass Spectrom., 17,... 

Until about the 1990s, visible light played little intrinsic part in the development of mainstream mass spectrometry for analysis, but, more recently, lasers have become very important as ionization and ablation sources, particularly for polar organic substances (matrix-assisted laser desorption ionization, MALDI) and intractable solids (isotope analysis), respectively. 

Some solid materials are very intractable to analysis by standard methods and cannot be easily vaporized or dissolved in common solvents. Glass, bone, dried paint, and archaeological samples are common examples. These materials would now be examined by laser ablation, a technique that produces an aerosol of particulate matter. The laser can be used in its defocused mode for surface profiling or in its focused mode for depth profiling. Interestingly, lasers can be used to vaporize even thermally labile materials through use of the matrix-assisted laser desorption ionization (MALDI) method variant. 

Two relatively new techniques, matrix assisted laser desorption ionization-lime of flight mass spectrometry (MALDI-TOF) and electrospray ionization (FS1), offer new possibilities for analysis of polymers with molecular weights in the tens of thousands. PS molecular weights as high as 1.5 million have been determined by MALDI-TOF. Recent reviews on the application of these techniques to synthetic polymers include those by Ilantoif54 and Nielen.555 The methods have been much used to provide evidence for initiation and termination mechanisms in various forms of living and controlled radical polymerization.550 Some examples of the application of MALDI-TOF and ESI in end group determination are provided in Table 3.12. The table is not intended to be a comprehensive survey. 

Choudhary, G., Chakel, J., Hancock, W., Torres-Duarte, A., McMahon, G., and Wainer, I., Investigation of the potential of capillary electrophoresis with offline matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for clinical analysis examination of a glycoprotein factor associated with cancer cachexia, Anal. Chem. 71, 855, 1999. 

Wigge, P. A., Jensen, O. N., Holmes, S., Soues, S., Mann, M., and Kilmartin, J. V. (1998). Analysis of the Saccharomyces spindle pole by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. J. Cell Biol. 141, 967-977. 

Wahl, K. L. Wunschel, S. C. Jarmon, K. H. Valentine, N. B. Peterson, C. E. Kingsley, M. T. Zartolos, K. A. Saenz, A. J. Analysis of microbial mixtures by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Anal. Chem. 2002, 74, 6191-6199. 

Krishnamurthy, T. Ross, P. L. Rapid identification of bacteria by direct matrix-assisted laser desorption/ionization mass spectrometric analysis of whole cells. Rapid Commun. Mass Spectrom. 1996,10,1992-1996. 

The focus of this chapter is the development of a technique often called wholecell matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) or whole-cell MALDI-TOF MS. Some groups prefer to use terms such as intact or unprocessed rather than whole, but the intended meaning is the same regardless of which word is used. As noted in the first chapter of this book, there are many different methods for the analysis of bacteria. However, for the analysis of intact or unprocessed bacteria, whole-cell MALDI-TOF MS is the most commonly used approach. This method is very rapid. MALDI-TOF MS analysis of whole cells takes only minutes because the samples can be analyzed directly after collection from a bacterial culture suspension. Direct MALDI MS analysis of fungi or viruses is similar in approach1,2 but is not covered in this chapter. MALDI-TOF MS of whole cells was developed with very rapid identification or differentiation of bacteria in mind. The name (whole cell) should not be taken to imply that the cells are literally intact or whole. Rather, it should be taken to mean that the cells that have not been treated or processed in any way specifically for the removal or isolation of any cellular components from any others. In whole-cell analysis the cells have been manipulated only as necessary to... 

Wang, Z. Russon, L. Li, L. Roser, D. C. Long, S. R. Investigation of spectral reproducibility in direct analysis of bacteria proteins by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Rapid Comm. Mass Spectrom. 1998,12,456-464. 

Reschiglian, P. Zattoni, A. Cinque, L. Roda, B. Dal Piaz, F. Roda, A. Moon, M. H. Min, B. R. Hollow-fiber flow field-flow fractionation for whole bacteria analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Anal. Chem. 2004, 76,2103-2111. 

The introduction and eventual commercialization of matrix-assisted laser desorption/ionization (MALDI) and electrospray (ESI) allowed biomarker status to be extended to proteins in 1996.15"17 With a few exceptions, ESI has been used in conjunction with extractions and high-pressure liquid chromatography (UPLC) interfaced with mass spectrometry. MALDI, on the other hand, has been widely adapted for rapid analysis of intact organisms, supported by bioinformatics.1819... 

---