The culture supernatant protein digestion kit from MtoZ Biolabs is specifically designed for cell culture medium samples, balancing background removal and protein recovery efficiency while optimizing digestion conditions to significantly enhance MS compatibility and the number of identified proteins. It is suitable for various research applications, including secretome analysis, conditioned medium profiling, and extracellular vesicle studies, and is compatible with multiple mass spectrometry platforms such as Orbitrap, TripleTOF, and TIMS-TOF.
As a simulated extracellular environment, cell culture medium is widely used to investigate cellular secretion mechanisms, cell-cell communication, exosome release, and drug response. However, proteins in directly collected culture supernatant are typically low in abundance and accompanied by high levels of salts and surfactants, which result in substantial background interference. These issues severely compromise downstream digestion efficiency and mass spectrometry detection sensitivity, posing a technical bottleneck in secretome analysis.
High-abundance background proteins introduced by additives such as FBS (fetal bovine serum) or BSA can mask low-abundance, cell-derived protein signals, leading to biased MS detection. In addition, proteins in the supernatant are prone to degradation, and conventional enrichment methods like TCA or ethanol precipitation often cause significant protein loss and poor resolubilization, making it difficult to standardize digestion procedures.
To address these challenges, MtoZ Biolabs has developed the culture supernatant protein digestion kit that can be used for digesting low-abundance, complex-background samples. The kit features optimized protocols for protein denaturation, reduction, alkylation, and enzymatic digestion, coupled with a unique reaction system that significantly improves digestion efficiency and protein identification coverage, ultimately enhancing the sensitivity and reliability of proteomic analysis from culture supernatant samples.
Product Overview
The culture supernatant protein digestion kit from MtoZ Biolabs is a ready-to-use kit specifically designed for processing low-abundance proteins in cell culture supernatants. It is compatible with standard culture media systems (such as FBS-containing or serum-free DMEM, RPMI-1640, MEM, IMDM, etc.). The core components include an optimized lysis buffer, a denaturation/reduction/alkylation mix, high-activity trypsin, and a specialized reaction buffer system, ensuring efficient denaturation and enzymatic digestion of proteins under mild conditions.
Product Features
- Effectively removes interfering components such as salts, sugars, and serum proteins from culture media.
- High digestion efficiency, suitable for high-coverage identification of various secretome proteins.
- Simple workflow with a high degree of standardization, supports automated processing.
- Each kit can process 8 samples, suitable for research and screening applications.
In addition, the culture supernatant protein digestion kit is compatible with various culture supernatant processing workflows, including:
- Standard media (DMEM, RPMI-1640, MEM, etc.).
- Serum-containing and serum-free culture samples.
- Conditioned media samples (e.g., drug stimulation, hypoxia treatment).
- Background removal pretreatment for exosome-containing supernatants.
Product Notes
1. Lysis Buffer 1 should be freshly prepared before use: mix components A and B.
2. After sample preparation, use immediately or aliquot and store at -80°C.
3. Avoid foam formation during operation to prevent interference with protein binding efficiency.
4. It is recommended to use low-protein-binding centrifuge tubes for collecting the eluent to avoid loss of low-abundance proteins due to adhesion to tube walls.
5. Protein concentrations may vary between different batches of culture supernatant samples; a preliminary experiment is recommended to determine the optimal concentration ratio and incubation time.
Product Details
|
Product Details |
Size |
Storage Conditions |
|
Wash buffer 1 |
2 mL×1 |
RT |
|
Wash buffer 2 |
8 mL×1 |
RT |
|
Lysis buffer 2 |
1.2 mL×1 |
RT |
|
Elution buffer 1 |
100 μL×1 |
RT |
|
Elution buffer 2 |
1 mL×1 |
RT |
|
Lysis bufferA |
3.75 mg×1 |
RT |
|
Lysis bufferB |
1 mL×1 |
RT |
|
Beads |
0.8 mg×1 |
4℃ |
|
Enzymes |
4 μg×1 |
-20℃ |
Protocol
MtoZ Biolabs' culture supernatant protein digestion kit provides a standardized yet flexible sample preparation workflow. The following protocol helps users easily prepare culture supernatant samples for enzymatic digestion, suitable for downstream LC-MS/MS analysis. If required, it can be adapted for special sample types or automated platforms based on experimental needs.
1. Sample Preparation
If the protein concentration in the culture supernatant is low, it is recommended to concentrate the supernatant prior to enrichment. Transfer 100-200 μL of concentrated culture supernatant to a clean microcentrifuge tube.
2. High-Abundance Protein Removal
(1) Add an appropriate volume of pre-washed magnetic beads to the corresponding volume of the culture supernatant sample.
(2) Mix thoroughly and incubate on a rotator for 10-15 minutes.
(3) Place the tube on a magnetic rack to separate the beads and perform bead washing.
(4) Lyse the low-abundance proteins off the beads.
3. Digestion of Low-Abundance Proteins
(1) Dilute the protein solution with digestion buffer and perform overnight enzymatic digestion.
(2) Recover the resulting peptide solution using the elution buffer.
4. Digestion Termination and Sample Cleanup (Optional)
If reaction termination or desalting is needed, apply the appropriate termination protocol or downstream cleanup module based on experimental requirements. The final peptides can be directly used for LC-MS/MS or other mass spectrometry platforms.
MtoZ Biolabs also offers end-to-end services including sample desalting, peptide enrichment, and mass spectrometry analysis, saving experimental cycles.
Features and Benefits
1. Compatibility with Complex Sample Matrices
Designed for media containing FBS or chemically defined formulations, significantly reducing background protein interference.
2. High-Efficiency Digestion System
Features stable enzymatic activity and high efficiency, enabling precise identification of low-abundance secreted proteins.
3. Standardized Workflow
Integrated operation steps minimize human error, improving experimental reproducibility and data consistency.
4. Compatible with Multiple Mass Spectrometry Platforms
Digestion products are suitable for Orbitrap, Q-TOF, TIMS-TOF, and other mainstream platforms.
5. Saves Time and Resources
Eliminates the need for cumbersome steps such as TCA/ethanol precipitation and membrane concentration, greatly reducing sample preparation time.
6. Supports High-Throughput Analysis
Adaptable to automated liquid handling platforms to meet large-scale sample analysis demands.
Applications
The culture supernatant protein digestion kit is broadly applicable in the following research areas:
1. Secretomics Studies
Investigating changes in secreted proteins under conditions of stimulation, stress, or disease.
2. Tumor Microenvironment Research
Analyzing proteins released by tumor cells or immune cells under co-culture conditions to identify tumor-associated extracellular signaling factors and potential biomarkers.
3. Cytokine and Growth Factor Analysis
Profiling small regulatory factors secreted by macrophages, T cells, stem cells, and other cell types.
4. Exosome and Extracellular Vesicle Protein Studies
After removal of soluble proteins, combining with exosome isolation for analysis of surface markers or internal cargo.
FAQs
Q1: Is the Kit Compatible with FBS-Containing Media? Will Serum Albumin Interfere with the Analysis?
A1: This kit has been specifically optimized for use with both FBS-containing and serum-free media. While high-abundance background proteins in FBS, such as albumin, may indeed interfere with the detection of low-abundance secreted proteins, this kit offers excellent anti-interference performance through its optimized buffer system and digestion conditions. To improve specificity and sensitivity in secretome analysis, it is recommended to use serum-free induction conditions or pre-depleted FBS treatment during experimental design.
Q2: Do You Provide Downstream Mass Spectrometry Services?
A2: MtoZ Biolabs not only provides high-quality sample preparation products but also operates advanced mass spectrometry platforms (e.g., Orbitrap Fusion Lumos, timsTOF Pro). We offer comprehensive one-stop services from protein digestion and peptide purification to LC-MS/MS analysis and data interpretation, covering quantitative methods (TMT, DIA, Label-free) and post-translational modification (PTM) analysis.
Q3: Can This Kit Be Used for Extracellular Vesicle-Related Samples?
A3: Absolutely. After removing free proteins from the supernatant, extracellular vesicle proteins can be directly processed using this kit for subsequent enzymatic digestion. The kit’s mild and efficient reaction system is compatible with membrane-associated proteins, making it suitable for high-quality identification of extracellular vesicle markers. When combined with MtoZ Biolabs’ exosome isolation and enrichment services, research depth and accuracy can be significantly enhanced.
