14 Questions
What is the main purpose of Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) in clinical laboratories?
To measure mass-to-charge ratios of particles for bacterial identification
What is the role of a protein matrix in the Matrix Assisted Laser Desorption Ionization (MALDI) process?
To aid in crystallizing the sample onto the target plate
Why is MALDI-TOF MS considered advantageous over conventional methods in clinical laboratories?
It offers high identification rates and fast turnaround time
What is needed for MALDI to desorb and ionize the sample before analysis?
A laser
What is the main function of Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) in clinical laboratories?
To identify bacteria and fungi
What is the purpose of the protein matrix in Matrix-Assisted Laser Desorption Ionization (MALDI)?
To buffer the sample and enable efficient ionization
Which component is NOT required for Matrix-Assisted Laser Desorption Ionization (MALDI)?
Chromatography column
What is the role of the ion source in Matrix-Assisted Laser Desorption Ionization (MALDI)?
To desorb and ionize the sample
How does Matrix-Assisted Laser Desorption Ionization (MALDI) differ from Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS)?
MALDI separates ions by time of flight, while MALDI-TOF MS separates ions by mass-to-charge ratios
What is the approximate time taken for analysis per sample using Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS)?
$2-3$ minutes
What is the role of the detector in Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS)?
To analyze the mass spectrum
Which commercial systems are available for Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) in clinical labs?
Bruker, Shimadzu, bioMérieux
What is aided by the protein matrix in Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS)?
Crystallization onto the target plate
What does Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) offer compared to conventional methods?
Low cost, fast turnaround time, and high identification rates
Study Notes
- Dr. Robin Patel, CONLAB Microbiology Division Chair at Mayo Clinic, discusses Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) for bacterial identification in clinical laboratories.
- MALDI-TOF MS measures mass-to-charge ratios of particles to generate a mass spectrum used for identification.
- In the late 1980s, Matrix-Assisted Laser Desorption Ionization (MALDI) made protein analysis through mass spectrometry possible.
- MALDI uses a laser to release energy into the sample, which causes desorption and ionization, then separates ions by time of flight.
- MALDI requires a sample, protein matrix, ion source, mass analyzer, and detector.
- In the clinical lab, a colony is picked, mixed with a matrix, placed in the mass spectrometer, and analyzed. Analysis takes approximately 2-3 minutes per sample.
- The sample is crystallized onto the target plate, which is aided by the matrix, which buffers the sample and enables efficient ionization.
- The mass spectrum generated is compared to a comprehensive library of spectra for identification, often at the genus and species level.
- Multiple commercial systems are available for MALDI-TOF MS in clinical labs, including those from Bruker, Shimadzu, and bioMérieux.
- MALDI-TOF MS offers high identification rates, fast turnaround time, and low cost compared to conventional methods.
- MALDI-TOF MS can identify all types of bacteria and even fungi.
- However, limitations include the need for sample preparation for some organisms, potential misidentifications due to closely related species or database limitations, and the lack of susceptibility information.
- The technology is not yet approved by the US Food and Drug Administration for clinical use.
- In contrast to traditional bacteriology workflow that includes long biochemical tests and 16s rRNA gene sequencing, MALDI-TOF MS can directly identify colonies growing on plates.
Explore the use of Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) for bacterial and fungal identification in clinical laboratories. Learn about its process, comparison to traditional methods, limitations, and commercial systems available.
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