What is MALDI-TOF 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-TOF analysis?

Mass spectrometry is an analytical technique in which samples are ionized into charged molecules and ratio of their mass-to-charge (m/z) can be measured. In MALDI-TOF mass spectrometry, the ion source is matrix-assisted laser desorption/ionization (MALDI), and the mass analyzer is time-of-flight (TOF) analyzer.

Is Vitek MALDI-TOF?

VITEK® MS PRIME is a Matrix-Assisted Laser Desorption Ionization Time of Flight mass spectrometer (MALDI-TOF-MS). The device analyzes material from microbial cultures to provide microorganism identification.

What is the main use of MALDI-TOF in protein studies?

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.

Is MALDI-TOF accurate?

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. The identifying accuracy rate of bioMérieuxVitek MS was slight higher than Bruker MALDI Biotyper (75% vs 72%).

How long does MALDI-TOF take?

In our experience, teaching the use of MALDI-TOF MS to laboratory technician personnel, including the protein extraction procedure, requires only about 1 h.

What is the full form of MALDI-TOF?

The matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a rapid, accurate, and cost-effective method of microbial characterization and identification.

How much does a Maldi Tof cost?

The cost of identifying 21,930 organisms would have cost $84,491 in reagents alone. With MALDI-TOF, Gilligan’s team has results often within an hour, depending on the type of organism. And the cost of materials was $6,469 for one year.

What is Vitek used for?

VITEK 2 Automated Systems VITEK 2 is a fully automated system that performs bacterial identification and antibiotic susceptibility testing. User interface screen for immediate notification of system status to increase productivity. Unique vacuum filler provides both safety and the highest level of automation.

Why is MALDI-TOF better?

In many cases it has shown resolution and reproducibility which is better than gel-based protein or DNA fingerprinting techniques (van Baar, 2000; Fenselau and Demirev, 2001; Lay, 2001). Numerous studies have shown that MALDI-TOF MS is a rapid, reliable and cost-effective technique for identification of bacteria.

Who invented MALDI-TOF?

Franz Hillenkamp
The term matrix-assisted laser desorption ionization (MALDI) was coined in 1985 by Franz Hillenkamp, Michael Karas and their colleagues. These researchers found that the amino acid alanine could be ionized more easily if it was mixed with the amino acid tryptophan and irradiated with a pulsed 266 nm laser.

How does the MALDI-TOF work?

In the case of MALDI-TOF, the analyzer separates molecules based on the time it takes each of them to fly through the time-of-flight tube or “drift” region to the detector. The ionized sample molecules are accelerated by a high-voltage current and fly through the tube before striking the detector.

How is the mass reflectron used in TOF-MS?

In a TOF-MS configuration named the ‘mass reflectron’, Mamyrin and Shmikk found a way to increase resolution by employing an electrostatic ion mirror in the drift region. The effect of initial velocity and spatial dispersions is minimized by applying a strong single acceleration field and this creates a spatial focus at 2s1 in the drift region.

How is the retarding field determined in a reflectron?

In single-stage reflectrons with homogeneous field, a zero field in a field-free region of a flight tube and the homogeneous field inside the ion mirror are separated by highly transparent (~95%) metal grid. The grid position is then referred as the entrance (exit) to the ion mirror and is used to calculate the retarding electric field.

How big is the mass resolution of a reflectron?

Mass resolution of the reflectron measured over broad mass range is much larger than that in a simpler (so-called linear) time-of-flight mass spectrometer comprising a pulsed ion source, flight tube, and ion detector. The masses of ions analyzed in the reflectron can span from a few Daltons to a few million Daltons.

How is the spread of flight times caused by the reflectron?

Using the reflectron, one can substantially diminish a spread of flight times of the ions with the same mass-to-charge ratio ( m/z) caused by spread in kinetic energy of these ions measured at the exit from the ion source.