Mass spectrometry: the supply side

In the last 10 years, we've seen a dizzying array of new variations of mass spectrometry instruments, and at the same time as we've seen radical changes in scientific discovery. Mass spectrometry has become a key tool across the life sciences, from discovery to routine lab work. Consequently there seems to be an almost limitless range of permutations of mass spec.

But one of the biggest drivers of the last few years has been the boom in protein research. According to John Hewetson of Shimadzu Biotech, about half of all the technical contributions to the recent American Society for Mass Spectrometry meeting in Orlando, Florida, involved proteomics, and improvements in mass spectrometry performance had been driven by the analysis requirements of proteomics.

"In the past, the main purpose of mass spectrometry in proteomics has been the identification of proteins," Hewetson said. "The emphasis has now shifted to technologies that enable structural elucidation of novel proteins and characterisation of post-translational modifications."

In the case of Shimadzu Biotech, he said, this was the driver for the development of the AXIMA-QIT, a hybrid MALDI-quadrupole ion trap- reflectron time-of-flight mass spectrometer, capable of MSn. "Published results have shown the value of using MS/MS/MS/MS/MS for the effective characterisation of sugar linkages in oligosaccharides," Hewetson said.

He said a key player in the Australian proteomics market was Proteome Systems (a partner with Shimadzu and Sigma-Aldrich in the Proteomics Alliance), which has six AXIMA-CFR's in its discovery laboratory. "This is by far the highest population of MALDI mass spectrometers, and possibly the only site in Australia practicing high-throughput proteomics," Hewetson said.

Bruker's Dr Peter Kesners said Bruker had been designing innovations for proteomics for the last decade, and pointed out that attention to detail was important. "For example, Bruker's AnchorChip sample preparation methodology saves money by eliminating the use of costly C18-based purification, while enhancing sensitivity and facilitating automation of analysis," he said.

"In Australia we are working with a very knowledgeable mass spec community that readily accepts high-end products, such as our range of FTMS systems. Australia already has the highest density of FTMS per population worldwide. There is also a brisk demand for our new TOF-TOF instruments, which are increasingly becoming popular as workhorses for proteomics projects."

Kesners said the different flavours of high-energy fragmentation (CID, LID, ISD) available in MALDI TOF-TOF were opening new ways of thinking in proteomics. "The distinction of leucine from isoleucine from side-chain fragmentation facilitates the de novo sequencing of peptides," he said. "The full exploitation of the MALDI process at low source pressures also affords sequence information even from whole undigested proteins up to 60 KDa."

Varian Australia has perhaps made some of the biggest changes of any instrument manufacturer in the last decade as its traditional industrial customer base is augmented with life science clients. That means its LC-MS systems now have to have built-in flexibility, according to the company's optical spectroscopy operations manager, Philip Binns. "From our perspective the opportunities for LC-MS are still growing," Binns said. "That's a large reason why we've developed our system around flexibility.

"LC-MS is becoming one of the endemic tools in the industry, for environmental research, drug discovery and biomolecular work. As the list of applications has grown, so has the interest in LC-MS as a tool."

What's on offer: a sample

• Agilent: newest instruments are the Nanoflow Proteomics Solution, which combines nanoflow HPLC technology capable of both 1D and 2D separations with MS/MS technology, and the atmospheric pressure MALDI source for the LC/MSD Trap system, for fast sample screening or more detailed investigations. In LC-MS the company provides the 1100 Series HPLC Systems for nanoscale separations through to 100 mL/min preparative applications. Also: mass-based purification systems; electrospray, APCI, APPI, nanospray and AP-MALDI sources; 1100 Series LC/MSD Quadrupole systems; and 1100 Series LC/MSD Trap systems.
• Bruker: starting with Ion Traps, covers QTOF, TOF and TOF-TOF and FTMS instruments. Ionisation methods ESI and MALDI are available in offline or online nano-electrospray; the MALDI process can be performed in different pressure domains ranging from atmospheric pressure to high vacuum. Demand for peptide and protein sequence data is met with MS/MS capabilities including PSD, LID, ISD,ECD, and IRMPD and CID at high and low energy levels. Current hot products in proteomics are the TOF-TOF, the 2D-LC IonTrap and the FTMS.
• Shimadzu: For MALDI-MS, the company provides its AXIMA-LNR, AXIMA-CFR, AXIMA-QIT and Xcise sample preparation unit. In LC-MS, it has the QP-8000 and LCMS-2010. In GC-MS there's the GCMS-QP5000 Electron Ionisation (EI) system, which analyses compounds within a mass-to-charge ratio of 10-700 AMU, the GCMS-QP5050A EI system with wide mass range detection, and the new GCMS-QP2010 with scansensitivity over 60/1 for lpg OFN and acquisition speeds to 50 scans per second.

Upcoming product launches:

• Agilent: A new atmospheric pressure ionisation TOF mass spectrometer system will be available at the end of 2002.
• Shimadzu: Next generation AXIMA-CFR, and the PsiPort Mass Directed Autopurification System.
• Varian: to launch its new small-footprint 1200L LC-MS system in August. Can be supplied with either GC-MS or LC-MS interface or both.