MALDI Source: SYNAPT G2 MS/HDMS series instruments

SYNAPT G2 MS/HDMS™ series instruments installed with a MALDI source accessory provide you with a no-compromise solution for the exact mass characterization of compounds using MALDI-MS, MALDI-MS/MS, and MALDI-MS/IMS/MS (SYNAPT G2 HDMS series) analyses.

Compound identification by mass spectrometry can be limited by the incompatibility of some molecules with electrospray ionization. Your SYNAPT series MS/HDMS instrument can overcome this limitation with the addition of an exchangeable Intermediate Pressure (IP) MALDI source offering:

• Dual ionization capability
• Significant increase in the number of compounds ionized and analyzed
• Compatible with 96/384 spot target plate formats
• MS and MS/MS analysis with high resolution, sensitivity and mass measurement accuracy
• 2.5KHz solid state laser system for MALDI SYNAPT G2, G2-S, and G2-Si instruments

Additionally, the ion mobility separation capability of SYNAPT HDMS series instruments enables components previously invisible to traditional MALDI analyses to be revealed, allowing species of interest within complex biological extracts to be separated from isobaric co-eluting compounds, MALDI matrix ions or background interferences.

MALDI Source in position (viewed from rear).

Rapid Changeover

All instruments feature a unique, motorized engagement system which enables the rapid and easy changeover between API and MALDI modes of operation. Users exchange sources by first removing the API source and then with a motorized stage, raise the MALDI source before securing it in position. The complete process to change from API acquisition to MALDI Acquisition can typically be achieved in two hours.

The exact mass MALDI-MS/MS data provided by SYNAPT series MS/HDMS instruments provide:

• Improved protein identification and protein sequence coverage
• Characterization of proteins and PTMs using exact MALDI-MS and MS/MS technology
• Significantly improved de novo sequencing compared to post-source decay (PSD) techniques
• Sensitive, accurate analysis of polymers, glycans, small molecules and oligonucleotides
• Metabolite identification and profiling
• Biomarker discovery
• Molecular imaging

The MALDI SYNAPT G2 HDMS series instruments with their additional ion mobility separation capability also offers the possibility of ground breaking experimentation in new areas of research.

LC-MALDI

Specific proteins from within complex mixtures that are only ionized by MALDI, can also be accommodated by first carrying out liquid chromatography separations followed by MS analyses.

An off-line LC separation is carried out and a robotic spotting device is used to spot the eluting LC fractions directly onto a MALDI target plate. This is then introduced into the instrument for MALDI analysis.

This procedure is particularly effective for protein identification using peptide mass fingerprinting where low-abundance and high-abundance proteins are mixed together.

With other traditional methods low-abundance proteins are undetected due to ion suppression effects, instrumental dynamic range limitations and chemical noise interferences.

LC MALDI analyses provide:

• Chromatographic separation spatially preserved on the MALDI target
• Generation of high sensitivity, interference-free, off-line LC-MS and LC-MS/MS data by MALDI
• Peptide mass mapping of low-abundance proteins in mixtures containing high-abundance proteins

MALDI image showing distribution of multiple low
mass molecules (purple overlay). Image generated
with BioMap (Novartis) software.

MALDI MS Imaging

The MALDI source accessory offers you the possibility of carrying out MALDI MS imaging on MALDI SYNAPT™ G2 series MS/HDMS™ systems. This can be further extended to include novel ion mobility studies with MALDI and MS imaging for the SYNAPT G2 HDMS series instruments.

MALDI imaging has the potential to enable misfolded proteins in tissue samples to be detected and so enhance the understanding of various human diseases.

The MALDI G2 SYNAPT series MS and HDMS sources all include as standard a microscope plate holder assembly enabling the direct introduction of conventional microscope plates.

Furthermore, MALDI SYNAPT G2, MALDI SYNAPT G2-S, and MALDI SYNAPT G2-Si series instruments are equipped as standard with a 2.5KHz high repetition rate solid state laser system, offering reduced ablation times for MALDI Imaging experiments. Average laser spot size has been reduced to 60µm in the current MALDI Source design.

Instrument Compatibility

Installation of the MALDI source is only recommended for the following instruments when already equipped with at least an 8,000 amu mass range quadrupole analyzer. However, there are some small molecule MALDI applications where a 4,000 amu quadrupole analyzer is satisfactory. The MALDI source can also be added to SYNAPT G2 series MS/HDMS instruments already equipped with the 32,000 amu mass range quadrupole analyser.

• SYNAPT G2 MS & SYNAPT G2 HDMS (2.5KHz laser)
• SYNAPT G2-S MS & SYNAPT G2-S HDMS (2.5KHz laser)
• SYNAPT G2-Si MS & SYNAPT G2-Si HDMS (2.5KHz laser)

On-site conversion of 4,000 amu quadrupole analysers to 8,000 amu mass range is also available for all SYNAPT series instruments.

Equipment and Installation

The MALDI source assembly includes a 2.5KHz solid state Nd:YAG laser system with dual axis sample inlet, providing full random access movement across each sample well. The high repetition rate laser, offers increased sample throughput together with excellent spatial resolution and improved productivity for MALDI imaging experiments. 

When configured for API operation, the MALDI source and vacuum system is fully retracted into the front of the new instrument enclosure.

For MALDI operation the new source is raised from its retracted position using an integrated motorized column, before being secured to the existing transfer housing using a tool free clamping system.

The source is compatible with all Waters sample plates and supports the option to incorporate lock mass sample wells for enhanced mass measurement accuracy. The source is also compatible with glass microscope slides and legacy Applied Biosystems target plates through use of a plate adaptor.

User controllable laser attenuation is included together with high magnification viewing optics that display a real-time image of the sample well on the instrument PC screen for acquisition purposes.

The complete MALDI source assembly requires installation by a Waters Field Service Engineer.