• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Texas A&M Forest Service
  • Texas A&M Veterinary Medical Diagnostics Laboratory
  • Texas A&M AgriLife Extension Service
  • Texas A&M AgriLife Research
  • Texas A&M College of Agrculture and Life Sciences
Texas A&M College of Agriculture and Life Sciences
Protein Chemistry Lab
  • Menu
  • Services
    • Amino Acid Analysis
      • Amino Acid Codes
      • AAA Assay Description
      • AAA Instrumentation
      • AAA Quantitation and Data Analysis
      • AAA Sample Preparation
      • AAA Sample Submission
    • Protein Sequence Analysis
      • Edman Experimental Procedure
    • Mass Spectrometry
      • Protein/Peptide Mass Determination
        • MS Mass Instrumentation
        • MS Mass Sample Preparation
        • Procedure for MALDI-TOF Analysis
        • Procedure for Electrospray Mass Analysis
        • Accuracy of the Analysis
      • Protein Identification-Proteomics
        • MS Protein ID Instrumentation
        • Sample Preparation and Purity
        • PMF/PSD
        • LC/MS/MS
        • Accuracy of the Analysis
        • In-gel Digestion of Proteins
    • Electrophoresis
      • SDS-Polyacrylamide Gel Electrophoresis
      • 2 Dimensional Gel Electrophoresis
      • DIGE
    • Chromatography
      • Chromatography Instrumentation
      • Normal Phases
      • Reversed Phase
  • Forms
    • Amino Acid Analysis
    • Protein Sequence Analysis
    • Protein/Pectide Mass Determination
    • Protein Identification/Proteomics
    • Electrophoresis
    • Chromatography
  • Staff
    • Gayan Nawaratna, Ph.D.
  • Fee Schedule
  • Policies & Timetables
  • Lab Instruments
  • References
  • Useful Links
  • Protocols by pdf

Accuracy of the Analysis

The Shimadzu/Kratos Axima CFR MALDI-TOF mass spectrometer is used for high accuracy peptide mass determination.  It is also used for Peptide Mass Fingerprinting of proteins.  The instrument is a Reflector with Post Source Decay capabilities for limited peptide sequencing.

Resolution of the instrument is ~10,000 allowing monoisotopic resolution up to ~2000 m/z.

The Axima has a mass accuracy of ~20 ppm (0.002%) in the range of 100 – 2000 m/z in the reflector mode with decreasing accuracy (~200 ppm) above 2000 m/z.

Sensitivity is 50 fmol of Angiotensin II (signal/noise is ~3 in this range) although it is most useful above 100 fmol.

Post Source Decay can be used to determine short stretches of amino acid sequence information from selected peptides.  This is a useful tool for helping to confirm protein identifications after in gel digestion.

  • MS Protein ID Instrumentation
  • PMF/PSD
  • LC/MS/MS
  • Accuracy
  • Sample Preparation
  • Digestion
  • Submittal Form
  • Compact with Texans
  • Privacy and Security
  • Accessibility Policy
  • State Link Policy
  • Statewide Search
  • Veterans Benefits
  • Military Families
  • Risk, Fraud & Misconduct Hotline
  • Texas Homeland Security
  • Texas Veterans Portal
  • Equal Opportunity
  • Open Records/Public Information
Texas A&M University System Member