Tag: MALDI-TOF MS

Explaining the manuscript: Teaching microbial identification using MALDI-TOF MS

June 11, 2022

During master’s studies, I chanced upon a relatively new microbial identification technique that uses mass spectrometry to profile the proteins of a microbe for identification purposes. The technique is known as matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS). I read a few application notes from Bruker Daltonics and picked up the technique. … More Explaining the manuscript: Teaching microbial identification using MALDI-TOF MS

Cluster analysis of microbial mass spectra could not infer phylogenetic relationships

August 23, 2018

Cluster analysis classify entities based on their degree of similarity. In the area of mass spectra analysis for microbial identification, cluster analysis has been used in classifying different mass spectra depending on the extent of similarity in mass peaks profiled. However, the approach could not infer phylogenetic relationship between species. Given that mass spectra that … More Cluster analysis of microbial mass spectra could not infer phylogenetic relationships

MALDI-TOF mass spectrum of bacteria depends on their growth state

August 7, 2018

A mass spectrometer profiles for the set of molecules whose abundances exceed the minimum sensitivity of the instrument. Thus, highly abundant biomolecules would be more likely to be profiled and featured on the corresponding mass spectrum of the sample. In the case of profiling of biomolecules from microbial cells using the technique of matrix-assisted laser … More MALDI-TOF mass spectrum of bacteria depends on their growth state

Conserved mass peaks of bacteria at the genus level

May 14, 2018

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been validated to be useful in identifying many microbial species to the species level. However, the approach relies on the existence of different mass peaks between different microbial species. Such differences manifest as differences in mass peak distribution in mass spectra of microbes that could be … More Conserved mass peaks of bacteria at the genus level

Theoretical ribosomal protein mass fingerprint database

April 25, 2018

Ribosomal proteins constitute the large and small subunit of the ribosome. Given the highly conserved nature of ribosomes, ribosomal proteins are expected to be similarly conserved. However, theoretical calculations of the molecular mass of ribosomal proteins of different species revealed the existence of distinct molecular mass fingerprint of ribosomal proteins from individual species. Such ribosomal … More Theoretical ribosomal protein mass fingerprint database

High accuracy timing mechanisms in time-of-flight mass spectrometers enable high mass resolution detection

March 22, 2018

High accuracy timing in time-of-flight mass spectrometers facilitate the accurate detection of time of arrival of different molecular ions, which when compared to a calibration chart of protein standards with known molecular weight, enables the calculation of mass/charge ratio of high mass resolution. Specifically, accuracy of the timing mechanism at the millisecond timescale provides a … More High accuracy timing mechanisms in time-of-flight mass spectrometers enable high mass resolution detection

Existence of ribosomal protein mass fingerprint of different bacterial, archaeal and eukaryotic species

March 12, 2018

Ribosomes are known to be highly conserved due to the importance of protein synthesis to cellular maintenance. Thus, constituent ribosomal proteins should theoretically be highly conserved, which implied a conserved amino acid sequence and molecular mass. However, unique molecular mass fingerprint of ribosomal proteins of individual species in the three domains of life was detected. … More Existence of ribosomal protein mass fingerprint of different bacterial, archaeal and eukaryotic species

Conserved mass peaks in mass spectra of bacterial species

February 2, 2018

Conserved mass peaks were found in mass spectra of individual bacterial species that highlighted a deep biological basis in the use of mass spectrometry for identifying bacteria. Specifically, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) could profile biomolecules (mostly proteins) from bacterial cells that result in a mass spectrum useful for identification purposes. While … More Conserved mass peaks in mass spectra of bacterial species

Long flight tube in time-of-flight mass spectrometer enables better separation of different analyte ions

January 23, 2018

Molecular ions literally fly through the flight tube of the time-of-flight mass spectrometer where at the end of the travel, they are detected as an electrical charge on the detector. The duration of flight was measured and is a key parameter for calculation of the mass/charge ratio of the molecular ion based on a calibration … More Long flight tube in time-of-flight mass spectrometer enables better separation of different analyte ions

Transfer of laser energy from matrix coating helps prevent fragmentation of molecules

January 19, 2018

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) ionizes molecules without inducing fragmentation, thereby allowing molecular ion to be detected, which helps data interpretation of mass spectrum. The mechanisms underlying the ability of the mass spectrometry technique to ionize molecules without inducing fragmentation lies in the use of special matrix compounds that help transfer laser … More Transfer of laser energy from matrix coating helps prevent fragmentation of molecules