Figure 2: MALDI TOF MS spectra and score values of bacteria cultured for various periods (A, B) and on various culture media (C, D). (A) MALDI TOF spectra of E. coli cultured for 5, 18, 24, and 48h on Columbia blood agar. (B) Score values obtained by MALDI TOF analysis of E. coli and S. aureus cultured for 5, 18, 24, and 48h on Columbia blood agar. (C) MALDI TOF spectra of E. coli cultured for 18 h on chocolate agar, Columbia blood agar, MacConkey agar, and Mueller-Hinton agar. (D) Score values obtained after MALDI TOF analysis of E. coli and S. aureus cultured for 18 h on Columbia blood agar (Blood), chocolate agar (Choc), Mueller-Hinton agar (MH), MacConkey agar (McC, E. coli only), and colistin / nalidixic acid agar (CNA, S. aureus only). Score values > 2.3 indicate highly probable species identification.