The overall low ion yield and sensitivity issues due to ion suppression, using traditional MALDI, make the imaging analysis of samples sometimes very challenging. Our answer to these problems is MALDI-2. The post-ionization technique reduces ion suppression effects and improves sensitivity by orders of magnitude.
After the initial MALDI process, a second laser, sitting parallel to the sample surface, fires into the evolving plume and post-ionizes neutral (mainly matrix) molecules. A charge transfer from post-ionized matrix molecules to neutral analyte molecules leads to an amazing sensitivity gain for many analytes.
MALDI-2 and microGRID – A powerful combination making the possibility of sub-cellular imaging within reach
The need for uncompromising post-ionization has never been greater. High spatial resolution below 10 µm results in a drastically decrease of ablated and ionized sample material. MALDI-2 post-ionization compensates the lower sample amount per pixel, making even the finest molecular distributions visible.
Combining MALDI-2 post-ionization with microGRID enabled high spatial resolution opens the field for the analysis of the smallest unit of eukaryotic life – single cells. This unique combination makes the timsTOF fleX MALDI-2 the platform of choice for out of the box single cell imaging.
Analyze cell structures that are otherwise only visible with a microscope and obtain molecule-specific information with (sub)cellular resolution.Complementing microGRID imaging with MALDI-2 post-ionization enhances the sensitivity detecting even the finest molecular distributions.
Post-ionization is easily accessible via software controlled solutions
The post-ionization laser is built as an add-on to the timsTOF fleX. All functions are exactly the same on the timsTOF fleX MALDI-2. This instrument is build on the latest timsTOF HT technology and combines the most advanced Omics analyses with high sensitive MALDI operation. No physical hardware changes are needed to activate post-ionization.
By just one click in the software the user will be able to change between post-ionization and traditional MALDI mode. This is done in seconds and allows for direct comparison of the two different ionization processes. You do not have to be a professional MALDI operator to use MALDI-2 as it is easy to handle and therefore also suitable for beginners.
Sensitivity
MALDI-2 increases sensitivity by up to 1-3 orders of magnitude depending on sample, analyte and matrix.
Dimensionality
MALDI-2 ionizes a wider range of chemical classes by reducing ion suppression effects, expanding chemical range for targeted analytes in MALDI Imaging.
TIMS and MALDI-2: Deep Content Imaging for Omics Context
Omics studies involving small molecules desorbed from tissues sections such as lipidomics and metabolomics typically involve biomolecules from a wide variety of chemical classes. These studies benefit from MALDI-2 as the technique provides access to many more compounds, providing unique insight into nature’s complexity. The combination of TIMS and MALDI-2 is uniquely powerful as richer ion yields from the post-ionization process produce mass spectra with higher information content. TIMS provides fast orthogonal separation that efficiently unravels these complex spectra where each m/z can contain many overlapping features. The result is not only the ability to extract information from single isobars, but also exact masses that have different ion mobilities. Collisional Cross Section (CCS) values are recorded for each one of the spectral components for comparison to databases or LC-MS results.
MetaboScape® MALDI-2 database
Bruker supplies all elements needed for performing successful MALDI-2 experiments from the necessary matrix and IntelliSlides®, to expert application support, and intuitive and user-friendly software solutions.
fleXmatrix® for MALDI-2
Especially developed for use with the timsTOF fleX MALDI-2
Able to remain stable under vacuum conditions
MetaboScape® target lists
Target lists with MALDI-2 specific compounds available for different analyte classes and samples for automatic analyte annotation
MALDI-2: Leading the Pharma Tissue Model Revolution
A major limiting factor in modern drug development is use of the “well-stirred model” which homogenizes organs and tissues prior to analysis and quantitation with LC-MS studies. This approach is well-suited to providing exact amounts of drugs and metabolites within a target organ, but not readily compatible with pathology methods that seek to describe physiological effects of drug compounds.
MALDI Imaging has made a significant impact towards the conversion of plasma to tissue models by pinpointing the exact location of drugs and metabolites in tissue. MALDI-2 enhances molecular imaging for pharma studies by increasing overall sensitivity enabling quantitation for a wider range of dosing levels. Additionally, the increased variety of molecular classes seen by MALDI-2 expands the applicability of imaging to many more pharma projects that involve both xenobiotics and endogenous molecules.
Drug imaging from dosed tissue (Chloroquine)
MALDI-2 improves limits of detection for several analytes
MALDI-2 boosts signal intensities for drug compounds that do not traditionally ionize with MALDI
A study comparing detection sensitivity from MALDI and MALDI-2. Dilution series or single dilutions of different analytes such as caffeine, prednisolone, estradiol, cortisol, doxorubicin, fluoxetin, kynurenine and paclitaxel were spotted onto liver homogenate and imaged with MALDI-2 on and off. Use of MALDI-2 clearly yields significantly higher sensitivity.
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