Why is MALDI used for imaging?
Because of its ability to perform molecular analyses while retaining morphological information, MALDI Imaging is very well suited to study molecular distribution patterns within a tumor.
What is MALDI used for?
Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) has become a widely used technique for the rapid and accurate identification of bacteria, mycobacteria and certain fungal pathogens in the clinical microbiology laboratory.
What is MALDI imaging mass spectrometry?
MALDI Imaging is a powerful mass spectrometry tool for mapping the distribution of molecules from a thin sample, ranging from small metabolites to large proteins, without molecular tags or labels.
What is MALDI and how does it work?
MALDI is a soft ionization that involves a laser striking a matrix of small molecules to make the analyte molecules into the gas phase without fragmenting or decomposing them. Some biomolecules are too large and can decompose when heated, and traditional techniques will fragment or destroy macromolecules.
How does mass spectrometry imaging work?
This technique is performed using a focused ionization beam to analyze a specific region of the sample by generating a mass spectrum. The mass spectrum is stored along with the spatial coordination where the measurement took place. Then, a new region is selected and analyzed by moving the sample or the ionization beam.
What is the function of a matrix in MALDI MS analysis?
The matrix performs two important functions: (1) it absorbs photon energy from the laser beam and transfers it into excitation energy of the solid system, and (2) it serves as a solvent for the analyte, so that the intermolecular forces are reduced and aggregation of the analyte molecules is held to a minimum.
How are samples prepared for MALDI?
Samples for MALDI analysis may be supplied either in solution or lyophilised. Ideally samples should be resuspended in an aqueous solution of 50% (v/v) acetonitrile, 0.1% (v/v) trifluoroacetic acid using ultra high purity water. If any other solution is used, BioCentre staff must be supplied with comprehensive details.
What matrix is used in MALDI source?
laser-absorbing matrix
In MALDI, the tissue samples are completely coated with a laser-absorbing matrix, typically an organic compound of low molecular weight, which allows the extraction of the metabolites from the sample, also known as the analytes, upon matrix crystallization after solvent evaporation ( Table 2).
What is MALDI-TOF microbiology?
Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) is a powerful analytical mass spectrometry technique that has generated numerous diagnostic and clinical applications, especially for the identification of microorganisms for medical diagnosis.
What is MALDI identification?
The MALDI Biotyper® (MBT) is a microbial identification system based on MALDI-TOF mass spectrometry, allowing unbiased identification of microorganisms within a few minutes down to the species level.
What is instrumentation of mass spectrometry?
Mass spectrometer is an instrument that produces ions and separates them according to mass to charge (m/z) ration. The components of a mass spectrometer include ion source, mass analyzer, detector, and vacuum system. Various mass spectrometers have been developed to meet different challenging requirements.
What are the uses of mass spectrometry?
Specific applications of mass spectrometry include drug testing and discovery, food contamination detection, pesticide residue analysis, isotope ratio determination, protein identification, and carbon dating.
What is MALDI imaging?
MALDI imaging is a new technology that allows for direct mapping of peptides and proteins on tissue sections with a lateral resolution of 30–50 μm [47]. A MALDI matrix is deposited on the section and upon irradiation of the sample discrete spots are desorbed and analysed in MS, with a detectable mass range between m / z 400 and 30,000.
How is MALDI-IMS used in drug imaging?
Recently MALDI-IMS became available on instruments, that allow the measurement of mass signals with very high resolution and precision, namely Fourier-transform mass spectrometers (Cornett et al. 2008). In these instruments the necessary specificity of the drug imaging experiment can be reached by measuring the precise mass of the drug.
Is MALDI IMS a useful technique for lipid analysis?
CONCLUSION MALDI IMS has left its infancy and is becoming an established technique in various fields of biological research, especially for the analysis of lipids and drugs where alternative methods are scarce.
Why do we use the MALDI matrix for drug detection?
The mass range in which the drugs are measured is usually crowded by a large number of signals that come from the MALDI matrix as well as from lipids and naturally occurring substances. It is therefore necessary to ensure the necessary specificity of detection of a particular, probably small signal in between many other signals.
