How does Bruker MALDI work?
MALDI-TOF MS determines the unique proteomic fingerprint of an organism, and matches characteristic patterns with an extensive reference library to determine the organism´s identity. Continuous expansion of the reference library ensures that a broad range of microorganisms can be identified easily.
How do you analyze MALDI-TOF?
During MALDI-TOF analysis, the m/z ratio of an ion is measured by determining the time required for it to travel the length of the flight tube. A few TOF analyzers incorporate an ion mirror at the rear end of the flight tube, which serves to reflect back ions through the flight tube to a detector.
What is the principle of MALDI-TOF?
The principle of MALDI
During the ablation process, the analyte molecules are usually ionized by being protonated or deprotonated with the nearby matrix molecules. The most common MALDI ionization format is for analyte molecules to carry a single positive charge.
What molecule does MALDI-TOF identify?
After the matrix solution air-dried, the spotted samples were analyzed by MS (Jeong et al., 2013, 2014). MALDI-TOF MS has also been shown to be useful for detection of protein toxins, such as staphylococcal enterotoxin B, botulinum neurotoxins, Clostridium perfringens epsilon toxin, shiga toxin etc.
How does MALDI-TOF identify proteins?
One of the main uses of MALDI-TOF-MS is in the identification of proteins, by peptide mass fingerprinting (PMF). Here we describe a simple protocol that can be performed in a standard biochemistry laboratory, whereby proteins separated by 1D or 2D gel electrophoresis can be identified at femtomole levels.
How accurate is MALDI-TOF?
The MALDI-TOF MS correctly identified 92% of the M. tuberculosis isolates (95% CI of 0.87 to 0.96), and 68% of M. bovisisolates (95% CI of 27% to 100%) to the species level. Mycobacterium tuberculosis complex in solid media with reference strains using augmented database showing more accurate identification.
Is MALDI-TOF accurate?
Why is MALDI-TOF used?
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 are limitations of MALDI-TOF?
The most significant limitation of MALDI-TOF is its low analytical sensitivity without prior cultivation and the discrimination of phyletically related microorganisms such as Shigella and Escherichia coli [41] Consequently, MALDI-TOF is unsuitable for detecting the small number of bacteria in sterile samples.
Why is TOF preferred over other types of mass spectroscopy?
Samples can be measured faster and with no spectral skewing. For the same mass range, a TOF analyzer will measure each ion more sensitively. Since all ions are included in each simultaneous full-spectrum scan, no important information is missed or discarded.
How many organisms can MALDI-TOF identify?
For Gram-negative bacteria evaluation, there are 2263 clinical significant species can be analyzed by MALDI-TOF MS identification. Faron et al.
What is the major advantage of TOF?
Advantages of using TOF for broad spectrum analysis includes increased mass accuracy and mass resolution, greater sensitivity, rapid acquisition, and increased dynamic range when profiling over a broad molecular weight range.
What is the limitation of MALDI-TOF?
Why is ToF preferred over other types of mass spectroscopy?