MtoZ Biolabs employs high-resolution mass spectrometry platforms and has launched the accurate mass determination service to perform precise mass analysis and heterogeneity characterization of proteins and their variants. The service is widely applied in protein identification, integrity verification, and batch-to-batch consistency assessment, forming a critical basis for molecular composition analysis and data reliability.

Overview

Accurate mass refers to high-precision measurement of protein molecular mass. Enabled by high-resolution MS, the workflow ionizes samples and determines their mass by accurate mass-to-charge (m/z) detection, supporting resolution of small mass differences. This approach is broadly used for confirming recombinant protein identity, determining N-terminal processing and truncation forms, and resolving mass shifts from glycosylation isoforms. It strengthens qualitative and quantitative evidence chains and improves reliability in downstream protein bioanalysis.

Brenton, A G. et al. Journal of American Society for Mass Spectrometry, 2010.

Figure 1. Accurate Mass Determination by Mass Spectrometry.

Accurate Mass Determination Service at MtoZ Biolabs

MtoZ Biolabs provides precise molecular mass confirmation and critical quality attribute characterization of intact proteins using high-resolution mass spectrometry.

• Determines the accurate mass of intact proteins and protein subunits

• Interprets isotopic distributions and heterogeneous molecular forms

• Identifies common sources of mass shifts

• Enables multi-batch molecular mass comparability analysis

Our analysis delivers systematic insights into the molecular mass and heterogeneity state of proteins, empowering researchers to validate protein identity, assess structural integrity, and establish molecular-mass evidence chains for quality standard development.

Workflow of Accurate Mass Determination Service

1. Sample Preparation and Pre-treatment

Solubilize, desalt, and evaluate protein samples to ensure they are suitable for high-resolution mass spectrometry detection.

2. Ionization and Injection

Use appropriate ionization methods (such as ESI or MALDI) to convert molecules into charged ions and introduce them into the mass spectrometry system.

3. High-Resolution Mass Measurement

Use high-resolution platforms such as Orbitrap or TOF to acquire accurate-mass data and achieve high-precision measurement of mass values.

4. Data Calibration and Mass Correction

Perform mass calibration using internal or external standards to reduce instrument error and ensure the accuracy and reproducibility of mass measurement results.

5. Result Calculation and Comparative Analysis

Based on the measured accurate mass, calculate the molecular formula or isotopic distribution, and compare with databases or theoretical values to confirm molecular identity.

Why Choose MtoZ Biolabs?

• High-Precision Mass Determination: Uses high-resolution mass spectrometry to achieve precise determination at the molecular mass level.
• High-Sensitivity Analysis: Detects low-abundance targets and enables reliable analysis of trace samples.
• Stable and Reliable Data: Rigorous quality control ensures the consistency and reproducibility of mass determination results.
• Standardized Workflow: A standardized process accelerates data acquisition and shortens project timelines.
• One-Stop Analytical Support: Full-process coverage from sample handling to mass interpretation reduces the cost of experimental handoffs.

Applications of Accurate Mass Determination Service

1. Recombinant and Engineered Protein Confirmation

Accurate mass comparison between theoretical and measured values to verify recombinant proteins, fusion proteins, tagged proteins, antibodies, and their conjugated forms, confirming molecular identity and processing state.

2. Structural Integrity and Truncation Assessment

Identification of mass deviations caused by N/C terminal loss, domain deletion, subunit cleavage, degradation fragments, or incorrect proteoform assembly.

3. Multi-Batch and Cross-Platform Comparability

Accurate neutral mass comparison across different production or purification batches and among different MS platforms, supporting molecular mass evidence traceability.

4. PTM and Residue-Driven Mass Shift Analysis

High-precision determination of small mass shifts introduced by post-translational modifications or signature residues.

5. Mass Monitoring Under Defined Conditions

Accurate mass comparison of intact proteins or peptide analytes before and after specific experimental treatments or conditions, tracking molecular mass changes.

Deliverables

• Comprehensive Experimental Details
• Materials, Instruments, and Methods
• Protein molecular weight confirmation list
• Mass spectrometry images and peptide match spectra
• Bioinformatics Analysis
• Raw Data Files

FAQ

Q1: What types of samples are suitable?

A1: Samples with clearly defined origins and high purity are ideal, including purified proteins/peptides from various sample types, recombinant proteins, fusion proteins, and others. For samples containing complex matrices or low-abundance targets, pre-purification or desalting is recommended to improve mass measurement accuracy.

Q2: What is the service general workflow?

A2:

Q3: What data formats are provided?

A3: MtoZ Biolabs provides multiple standardized outputs, including:

• Mass spectrometry raw data files (e.g., .raw and other platform formats)

• Processed accurate mass result tables (Excel/CSV)

• PDF analysis report (including method parameters, mass error, isotopic distribution, and conclusions)

• Image files (mass spectra, isotopic envelopes, and calibration curves, PNG/TIFF)

If special analytical requirements exist, data formats can be customized according to project specifications.

Q4: How should I prepare samples?

A4: To ensure optimal determination performance, please prepare samples as follows:

• Sample Purity: Remove salts, detergents, glycerol, buffer salts, and organic impurities as much as possible; perform desalting or simple cleanup when necessary.
• Storage Conditions: 4℃ for short term, -80℃ for long term; minimize freeze-thaw cycles.
• Shipping: Transport at low temperature (ice packs/dry ice), use leak-proof packaging and clear labeling.
• Additional Information: Indicate protein source, theoretical molecular mass, solvent system, and preprocessing steps to support spectral matching and mass calibration.

For more information, please refer to Sample Submission Guidelines for Proteomics, Sample Submission Guidelines for Metabolomics.

Start Your Project with MtoZ Biolabs    

Contact us to discuss your experimental design or request a quote. Whether you are confirming the accurate mass and isotope distribution of protein molecules, or conducting impurity identification and quality consistency studies, we can provide you with high-precision data support.