Quantification Mass Spectrometry Service

Protein quantification can serve very different purposes depending on the study. In some projects, the goal is simply to determine total protein concentration, while in others, researchers need to measure specific proteins or peptides across samples, experimental groups, or concentration ranges.

Colorimetric methods such as BCA and Bradford are well suited to total protein measurement, but they do not provide target-specific information. LC-MS offers a more selective approach when individual proteins or peptides need to be quantified within complex biological samples.

 

Service at MtoZ Biolabs

MtoZ Biolabs provides LC-MS-based relative, absolute, calibration-based, and targeted quantification for predefined proteins and peptides. These workflows can support candidate verification, concentration measurement, treatment-response studies, time-course experiments, and follow-up analysis after discovery proteomics.

Our LC-MS workflows use Thermo Fisher Q Exactive HF, Orbitrap Fusion, and Orbitrap Fusion Lumos mass spectrometers coupled with Nano-LC systems, supporting high-resolution and high-mass-accuracy protein and peptide analysis.

For broader proteome-level studies, MtoZ Biolabs also provides TMT, iTRAQ, SILAC, Label-Free, DDA, and DIA quantitative proteomics services for large-scale protein identification and comparative analysis.

 

The quantitative approach is selected according to target type, sample matrix, expected abundance, quantitative range, and required output.

Project Need	Quantification Approach	Typical Output
Compare target abundance across samples	Relative Quantification	Relative abundance, ratio, or fold change
Determine protein or peptide concentration	Absolute Quantification	Concentration or absolute amount
Improve quantitative control	Stable Isotope-Assisted Quantification	Target-to-internal-standard response
Measure across a defined concentration range	Calibration-Based Quantification	Calibration-derived quantitative values
Quantify predefined proteins or peptides	Targeted LC-MS/MS	Target-specific quantitative results
Measure multiple predefined targets	Multiplex Targeted Quantification	Quantitative results for a defined target panel

Stable isotope-labeled peptides, calibration standards, PRM, or MRM/SRM can be incorporated when required. Additional sample preparation or enrichment may be considered for low-abundance targets or challenging matrices.

 

Analysis Workflow

1. Target and Sample Review

Review target proteins or peptides, sample type, sample amount, experimental groups, and quantitative requirements.

 

2. Sample Preparation and Assay Setup

Prepare samples and establish target peptides, reference standards, calibration ranges, internal standards, and acquisition parameters as needed.

 

3. LC-MS/MS Quantification

Analyze prepared samples using a high-resolution LC-MS/MS workflow matched to the target panel and quantitative objective.

 

4. Data Processing and Reporting

Process quantitative signals and report relative abundance, fold change, concentration, target-to-standard ratios, or other project-specific results.

Applications

LC-MS protein and peptide quantification can support:

• candidate protein verification;
• absolute protein concentration measurement;
• treatment and dose-response studies;
• time-course quantification;
• low-abundance target measurement;
• recombinant protein quantification;
• pathway-focused protein panels;
• follow-up analysis after discovery proteomics.

Why Choose MtoZ Biolabs?

1. State-of-the-Art Instrumentation

We combine multiple mass spectrometry technologies (including MALDI-TOF MS, ICP-MS, and Orbitrap MS) to meet diverse needs, from high-throughput screening to precise quantification.

2. High Sensitivity and Broad Dynamic Range

Capable of detecting concentrations from pg/mL to μg/mL, ensuring precise results even for low-abundance molecules.

3. Custom Solution

We tailor experimental protocols to your specific research goals, ensuring that our results meet your exact needs.

4. Rapid Turnaround

With our streamlined processes, results can typically be delivered within weeks under standard protocols.

5. One-Time-Charge

Our pricing is transparent, no hidden fees or additional costs.

Sample Submission Suggestions

1. Sample Types

Our LC-MS protein quantification service supports various sample types, including but not limited to:

• Cell or tissue lysates
• Serum and plasma
• Cell culture media
• Tissue homogenates
• Other biological samples (e.g., urine, saliva)

 

2. Sample Amount

Liquid Samples: A minimum of 50-100 μL is recommended to ensure sufficient sample volume and analytical accuracy.

Solid Samples: For tissue or cell samples, a minimum of 10 mg is recommended.

 

3. Sample Purity

To ensure accurate analytical results, samples should undergo appropriate purification processes. Samples containing significant impurities or interfering substances (e.g., lipids, RNA) may compromise the sensitivity of mass spectrometry analysis. Prior purification is strongly recommended in such cases.

 

Note: If you have specific requirements or need assistance with sample preparation, please feel free to contact us. We are here to help.

FAQ

Q1: What is the difference between relative and absolute protein quantification?

Relative quantification compares target abundance across samples or groups. Absolute quantification measures protein or peptide amount using an appropriate calibration or reference strategy.

 

Q2: Do I need a stable isotope-labeled internal standard?

Not for every project. Stable isotope-labeled peptides are particularly useful for internal-standard normalization, calibration-based measurement, or absolute quantification.

 

Q3: Can multiple proteins be quantified in one analysis?

Yes. Multiple predefined proteins or peptides can be included in a targeted panel when the targets and assay conditions are analytically compatible.

 

Start Your Project with MtoZ Biolabs

Send MtoZ Biolabs your target protein or peptide list, sample type, sample number, experimental groups, available material, expected abundance if known, and required quantitative output.

Our technical team can review target suitability and recommend an appropriate LC-MS/MS quantification strategy before quotation and project setup.

Free project consultation is available.