Maldi biotyper compass mbt compass

A qualitative analysis of the isolates was performed through MALDI-TOF MS. 5–10 mg of fresh mass from each isolate were placed in 300 μl Milli-Q water and 900 μl ethanol and then vortexed until homogenization. Samples were centrifuged at 14,500 × g for 2 min, pellets were dried at room temperature (RT), and subjected to 50 μl of 70% formic acid and 50 μl of acetonitrile. After a second centrifugation, proteins were obtained in the supernatant, and 1 μl was dried in a MALDI plate subsequently coated with 1 μl of HCCA matrix (α-cyano-4-hydroxycinnamic acid) prepared in a mixture of 50% acetonitrile and 2.5% trifluoroacetic acid. Samples were again dried at RT.
Dried samples were analyzed with MALDI-TOF/TOF “ULTRAFLEXTREME” (Bruker Daltonics, Bremen, Germany) equipment. Obtained spectra were treated with MALDI Biotyper Compass (MBT Compass; Bruker, MA, United States) software, calibrating the spectra before searching and matching, automatizing the measures and obtaining the identifications. Spectra were compared with reference profiles from the MBT Compass Library (Bruker) and finally, score values ≥ 1.70 were considered.

A qualitative analysis of yeast isolates was performed with MALDI-TOF mass spectrometry (Bruker Daltonics, Bremen, Germany). A colony from each isolate was placed in 300 μl distilled water and 900 μl ethanol and vortexed until homogenization. Then, samples were pelleted at 13,000 rpm for 2 min, and the pellet was dried at room temperature. Lastly, 50 μl of 70% formic acid and 50 μl of acetonitrile were added to the pellet. Samples were centrifuged for 2 min at 13,000 rpm, obtaining a supernatant with proteins.
About 1 μl of supernatant was dried at room temperature in a matrix-assisted laser desorption/ionization (MALDI) plate, and each sample was coated with 1 L of HCCA matrix (α-cyano-4-hydroxycinnamic acid) prepared in a mixture of 50% acetonitrile and 2.5% trifluoroacetic acid. Samples were again dried at room temperature.
Dried samples were analyzed with MALDI-TOF/TOF “ULTRAFLEXTREME” (Bruker Daltonics, Bremen, Germany) equipment. Generated spectra were treated with MALDI Biotyper compass (MBT Compass; Bruker, Billerica, MA, United States) software, which calibrates the spectra and automatizes the measures and identifications before searching and matching the results. Obtained spectra were compared with reference profiles from the MBT Compass Library (Bruker). Scores ≥2.0 were used as a selection criterion for identifications at species level (Kačániová et al., 2020 (link)).