Voyager DE-STR MALDI-TOF

Mass spectra of the digests have been successfully acquired in linear, negative-ion mode on both a Voyager DE-STR MALDI-TOF (horizontal instrument. Applied Biosystems, now Life Technologies) as well as a Voyager DE-PRO (vertical instrument). These are some of the most commonly available MALDI instruments on the market, and all protocol described here should be applicable to instruments of other manufacturers. Rgure 4.6 contains a typical spectrum acquired for two different bacterial samples using the Lane-AB primer pair as described above. 

Voyager DE-STR MALDI-TOF mass spectrometer with a 337 nm N2 laser (3 Hz) (Applied Biosystems, Foster City, CA, USA). 

A Voyager DE-STR MALDI-TOF mass spectrometer was used for the following description. Modification in instrumental conditions may be needed to achieve optimal imaging results when different instruments are used. 

The matrix-coated sample plate was loaded into the Voyager DE-STR MALDl-TOF mass spectrometer. The real-time video image of the tissue slice can be viewed via the video monitor. The tissue section boundaries were determined by their logical x and y coordinates on the MALDI plate. 

Matrix-Assisted Laser Desorption/lonization Time-of-liight Mass Spectrometry (MALDI-TOF MS, PerSeptive Biosystems Voyager-DE STR) was used to characterize the molecular weight distribution and the number average molecular weight (M ) of the poly(methacrylic acid) (PMAA) degradation products as described elsewhere [25]. 

Mass spectrometer (MALDI TOF Voyager-DE STR, Applied Biosystems, USA). 

FIGURE 4.4 MALDI-TOF mass spectrum acquired using a Voyager DE-STR (PerSeptive Biosystems) in linear mode of four peptides the mixture consisted of 1 pmole/ rL each of des-Arg -bradykinin, = 903.47 angiotensin I, = 1295.68 Glu-fibrin-... 

PE Corp http //WWW.pecorporation.com http //www.appliedbiosystems.com Symbiot workstation Voyager STR MALDI-TOF MS, the Voyager DE-PRO or the Mariner API-TOF LC-MS Protein Solution 1, SQL-LiMS, ProteinKeeper (under development)and Protein Prospector... 

Perform MALDI-TOF mass measurements in negative linear, delayed extraction mode. The precise measurement parameters will depend on the specific instrumentation used and require some optimization. As a guidehne, the instrument settings for a Voyager DE-STR instrument (Apphed Biosystems) can be found elsewhere (Seibert et al., 2002, 2008). 

H-NMR analyses were performed using a Varian 400 MHz spectrometer at room temperature. Samples were dissolved in CDCI3 (5 wt%). MALDI-TOF MS measurements were carried out on a Voyager-DE-STR instrument (Applied Biosystems, Foster City, CA, USA). Tra 5-2-[3-(4-teit-butylphenyl)-2-methyl-2-propenylidene] malononitrile was used as the matrix, which was dissolved in tetrahydrofuran (THF) at a concentration of approximately 40 mg/ml. Sodium trifluoroacetate (Aldrich, 98%, Milwaukee, WI, USA) was used as the cationization agent and was added to THF at a concentration of 5 mg/ml. Samples were dissolved in THF at a concentration of 2 mg/ml. In a typical measurement, the matrix, cationization agent and sample solution were premixed in a 5 1 1 ratio. Approximately 0.5 pi of the mixture obtained was hand-spotted on the target plate and left to dry. Mass spectra were recorded in the reflector mode. 

---