What is MALDI-TOF testing?
What is MALDI-TOF testing?
MALDI-ToF is a rapid microbiological method (RMM) that can be used to identify a wide variety of microorganisms. RMMs for microbial identification have been widely adapted by the clinical microbiology environment due to their speed and accuracy resulting in reduced risk and improved patient safety.
How does mass spectrometry identify bacteria?
A bacterial sample growing under defined conditions is subjected to standardized treatment. Highly abundant bacterial proteins are detected by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The protein mass patterns are generally in the range of 1,000 m/z (mass-to-charge ratio) to 20,000 m/z.
How do you interpret MALDI?
Interpreting a MALDI spectrum One is to regard it de novo, and to try to deduce, without other input, what the peptides might be. The other method, is to use a library of protein sequences, and to try to find proteins in the library which could have given rise to the peaks in the spectrum.
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.
How do you calculate mn from MALDI?
Polymer distributions are typically characterized by Mn and Mw, which are calculated from the formula: Mn = (NiMi)/Ni and Mw = (NiMi2)/NiMi Ni and Mi are the abundance and mass of the ith oligomer, respectively.
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.
