Data-Dependent Acquisition Service

DDA (Data-dependent acquisition) is an established LC-MS/MS strategy for discovery-oriented proteomics. During DDA analysis, precursor ions detected in an MS1 survey scan are selected in real time for fragmentation according to defined acquisition criteria, generating MS/MS spectra for peptide and protein identification.

MtoZ Biolabs provides Data-Dependent Acquisition Service for broad protein identification, exploratory proteome characterization, DDA-based label-free quantification, and identification-focused analysis of enriched or modification-containing samples. Acquisition settings are optimized according to sample complexity, chromatographic performance, and analytical objectives.

 

When This Service Is a Good Fit

DDA is particularly useful when confident peptide and protein identification is a primary analytical objective. Its precursor-specific acquisition strategy supports detailed MS/MS characterization and mature database-search workflows, making it suitable for discovery studies where protein identity, sequence coverage, or peptide-level information is important.

The Data-Dependent Acquisition Service may be appropriate for:

1. Broad protein identification in complex biological samples.

2. Exploratory proteome profiling where protein discovery is a major objective.

3. DDA-based label-free quantitative studies with suitable sample numbers and study design.

4. Enrichment-based studies requiring peptide- or protein-level identification.

5. PTM-focused projects requiring detailed characterization of modified peptides.

6. Experimental spectral library generation for selected DIA workflows.

For larger studies where consistent quantitative measurement across many samples is a major priority, DIA may offer better reproducibility and fewer missing values. For predefined proteins or peptides, PRM or MRM can provide focused targeted quantification.

 

Technical Principles

A typical DDA acquisition cycle begins with an MS1 survey scan. The mass spectrometer evaluates precursor ions detected within the selected mass range and sequentially isolates eligible ions for fragmentation and MS/MS acquisition. The resulting fragment spectra are used for peptide-spectrum matching and protein identification.

Dynamic exclusion temporarily prevents recently fragmented precursor ions from being repeatedly selected, allowing additional peptide species to be sampled during chromatographic elution. Because precursor selection depends partly on signal intensity, lower-abundance ions may not be selected consistently across repeated runs when many peptides co-elute. Acquisition settings are optimized to balance identification depth, chromatographic peak width, instrument speed, and cycle time.

Ryu, J. et al. Molecules. 2021.

Figure 1. Principles of Data-Dependent Acquisition (DDA)

Service at MtoZ Biolabs

MtoZ Biolabs provides DDA proteomics analysis using high-resolution LC-MS/MS platforms, integrating sample preparation, acquisition design, database searching, and downstream data analysis within the selected analytical scope.

1. Protein Identification and Proteome Profiling

High-resolution DDA LC-MS/MS is used to identify peptides and proteins from complex biological samples. Database-search parameters and identification criteria are selected according to the sample source, sequence database, and study objective, with false discovery rate control applied during identification.

 

2. DDA-Based Label-Free Quantification

DDA can be incorporated into intensity-based label-free quantitative workflows for exploratory comparison of protein abundance across biological groups. Quantitative results can be combined with statistical analysis and downstream functional interpretation when supported by the study design.

 

3. PTM-Focused DDA Analysis

DDA can be integrated with modification-specific enrichment and data-analysis strategies to identify and localize PTM-containing peptides. Sample preparation, enrichment, fragmentation, database searching, and site-localization analysis are adapted to the modification type and analytical objective.

The workflow can support phosphorylation, ubiquitination, acetylation, glycosylation, and other PTM-focused studies when appropriate enrichment and analytical strategies are included.

 

4. Protein Interaction and Enriched-Sample Analysis

DDA is well suited to identifying proteins in affinity-purified, immunoprecipitated, pull-down, and other enriched samples. These workflows can support identification of proteins associated with a bait protein, affinity reagent, compound, or experimentally defined target.

Protein- or peptide-level fractionation can also be incorporated before LC-MS/MS analysis for complex samples or studies requiring greater identification depth.

 

Analysis Workflow

1. Project Evaluation

Sample information and analytical objectives are reviewed to define the DDA workflow and determine whether enrichment or fractionation should be included.

 

2. Protein Preparation and Digestion

Proteins are extracted and prepared using procedures compatible with downstream mass spectrometry, followed by enzymatic digestion into peptides.

 

3. DDA LC-MS/MS Acquisition

Peptides are separated by nano-flow liquid chromatography and analyzed by high-resolution mass spectrometry using DDA settings selected according to sample characteristics and analytical objectives.

 

4. Database Search and Protein Identification

MS/MS spectra are searched against an appropriate protein sequence database to identify peptides and proteins under defined quality-control criteria.

 

5. Data Analysis and Biological Interpretation

Identification results are reviewed and organized according to the study design. When quantitative analysis is included, protein abundance data can be evaluated using statistical analysis, differential protein analysis, functional annotation, enrichment analysis, and pathway interpretation as appropriate.

 

6. Data Review and Delivery

Identification results, quantitative datasets, QC information, analytical documentation, and raw mass spectrometry data are organized for project delivery.

Why Choose MtoZ Biolabs?

1. Advanced Analysis Platform

MtoZ Biolabs established an advanced Data-Dependent Acquisition Service platform, guaranteeing reliable, fast, and highly accurate analysis service.

2. Customizable Service

Our Data-Dependent Acquisition Services are tailored to suit specific research objectives, providing flexibility in experimental design and maximizing the relevance of results.

3. One-Time-Charge

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

4. High-Data-Quality

Deep data coverage with strict data quality control. AI-powered bioinformatics platform integrates all data-dependent acquisition analysis data, providing clients with a comprehensive data report.

5. Fast Turnaround

The process from sample handling to report generation is efficient, shortening the analysis cycle.

 

Deliverables

Depending on the selected analytical scope, deliverables may include:

1. Experimental and LC-MS/MS Method Documentation

2. Protein and Peptide Identification Result Tables

3. Quantitative or PTM-Specific Results, When Included

4. Quality-Control and Statistical Analysis

5. Functional Annotation and Pathway Interpretation, When Included

6. Raw Mass Spectrometry Data and Processed Result Files

 

FAQ

Q1. Can DDA be used for quantitative proteomics?

Yes. DDA can support intensity-based label-free quantitative proteomics. Protein abundance is estimated from peptide ion signals across LC-MS/MS runs and compared among biological groups.

 

Q2. When is DIA more suitable than DDA?

DIA is often more suitable for larger quantitative studies where consistent measurement across samples and reduced missing values are major priorities. DDA remains well suited to identification-focused studies, exploratory proteome profiling, and peptide-level characterization.

 

Q3. Can DDA generate spectral libraries for DIA analysis?

Yes. Pooled or fractionated samples can be analyzed by DDA to generate experimental spectral libraries for library-based DIA workflows.

Predicted spectral libraries and library-free analysis are also available for modern DIA workflows, depending on the analytical strategy.

 

Contact MtoZ Biolabs

Contact MtoZ Biolabs with your sample type, study design, and analytical objective to discuss the appropriate DDA proteomics workflow and define the analytical scope before quotation.