i-Tracker

i-Tracker extracts reporter ion peak ratios from iTRAQ-labelled non-centroided tandem mass spectrometry peak lists and links quantitative information to peptide identifications from Mascot, Sequest, and other identification tools.

Key Features:

• Reporter Ion Peak Ratio Extraction: Extracts iTRAQ reporter ion peak ratios from non-centroided tandem MS peak lists for quantitative comparison across up to four-plex experiments.
• Compatibility and Integration: Associates quantitative information with peptide identifications from Mascot, Sequest, and similar search engines rather than requiring Applied Biosystems' Interrogator output used by ProQuant.
• Validation and Consistency: Has been validated against ProQuant (Applied Biosystems) and shown to produce consistent quantitative results.

Scientific Applications:

• Biomarker Discovery: Enables comparative quantitation across samples to identify candidate protein biomarkers.
• Differential Protein Expression: Facilitates measurement of relative protein abundance in differential expression studies.
• Large-Scale Proteomics: Supports integration of iTRAQ-based quantitative data into large-scale proteomics workflows.
• Pathway Analysis: Provides quantitative inputs for analyses of complex biological pathways.

Methodology:

Processes non-centroided tandem MS peak lists to extract iTRAQ reporter ion peak ratios and links those ratios to peptide identifications from external search engines.