96 target polished steel plate

E. ictaluri colonies were suspended in 300 µL of distilled water and mixed with 900 µL of absolute ethanol. After vortexing, the samples were centrifuged at 16,000 × g for 2 min, and the supernatant was decanted. The pellets were then resuspended in 500 µL of distilled water and centrifuged at 16,000 × g for 2 min. The supernatant was removed, mixed with 50 µL of absolute acetonitrile and 50 µL of 70% formic acid, and vortexed for 2 min. The sample was then centrifuged as described above, and 1 µL of the supernatant was targeted onto an MSP (main spectra library) 96-target polished steel plate (Bruker Daltonik). Next, the sample was dried, and 1 µL of α-cyano-4-hydroxycinnamic acid matrix solution (saturated solution of α-cyano-4-hydroxycinnamic acid in 50% acetonitrile and 2.5% trifluoroacetic acid) was added to the sample and allowed to crystalize.