Identification of a gram-negative isolate using MALDI-TOF is based on detecting which biomolecule?

Identification of a gram-negative isolate using MALDI-TOF is based on detecting which biomolecule?

• A. Cell wall carbohydrates
• B. Nucleotides
• C. Fatty acids
• D. Ribosomal proteins

Answer: (D)

MALDI-TOF identification rests on obtaining a distinctive mass fingerprint of the organism’s proteins, with ribosomal proteins providing the most informative signal. These small, abundant proteins generate strong, reproducible peaks in the mass spectrum that differ enough between species to create a unique pattern. The spectrum is then matched to a reference database to determine the organism’s identity. Because MALDI-TOF analyzes mass-to-charge ratios of ionized biomolecules, the practical basis of identification is ribosomal proteins rather than cell wall carbohydrates, nucleotides, or fatty acids.

MALDI-TOF identification rests on obtaining a distinctive mass fingerprint of the organism’s proteins, with ribosomal proteins providing the most informative signal. These small, abundant proteins generate strong, reproducible peaks in the mass spectrum that differ enough between species to create a unique pattern. The spectrum is then matched to a reference database to determine the organism’s identity. Because MALDI-TOF analyzes mass-to-charge ratios of ionized biomolecules, the practical basis of identification is ribosomal proteins rather than cell wall carbohydrates, nucleotides, or fatty acids.