|
Product Type |
Consumable |
Storage Conditions |
4 ℃ |
|
Bead Size |
10-30 μm |
Sample Volume Compatibility |
15 mL |
|
Product Size |
15 mL |
Shelf Life |
24 months |
In proteomics, metabolomics, and biomedical research, mass spectrometry (MS) has become an essential tool for studying proteins and peptides. However, during processes such as enzymatic digestion, chemical modification, or separation and purification, protein samples often accumulate large amounts of salts, detergents, or other small-molecule contaminants. These substances can significantly reduce MS detection sensitivity, cause signal suppression, and even damage the instrument. Therefore, desalting and purification steps are critical prior to MS analysis to ensure the accuracy and reliability of analytical results.
Traditional desalting methods, such as ultrafiltration, dialysis, gel filtration, and C18 solid-phase extraction (SPE), can remove salts and interferences to some extent. However, these methods are often limited by complex procedures, substantial sample loss, and long processing times. This is especially problematic in high-throughput workflows or when working with precious samples, where recovery and reproducibility are difficult to maintain. Magnetic bead-based technology has increasingly gained popularity in protein and peptide sample preparation due to its ease of operation, high automation potential, and consistent recovery performance.
Product Overview
The SP2 magnetic beads based peptide desalting kit from MtoZ Biolabs is based on advanced magnetic bead separation technology. Utilizing the specific adsorption properties of magnetic microspheres, it enables rapid removal of salts, detergents, and other interfering substances without the need for complex centrifugation steps, while ensuring high recovery rates and consistent mass spectrometry data quality. This kit is suitable for a wide range of peptide sample types, including protein digests, chemically synthesized peptides, cell lysates, and biofluids such as plasma/serum and urine. It is fully compatible with mainstream mass spectrometry platforms such as LC-MS/MS and MALDI-TOF, and can be widely applied in proteomics, metabolomics, biopharmaceutical research, and disease biomarker discovery.
Protocol
The SP2 magnetic beads based peptide desalting kit has been optimized for a streamlined and efficient workflow, making it suitable for various laboratory environments and experimental scales. The following is the recommended standard protocol, which can be adjusted according to specific research needs:
1. Bead Activation
Gently resuspend the SP2 magnetic bead slurry and transfer the desired volume to a centrifuge tube or 96-well plate.
(1) Use a magnetic rack to separate the beads and remove the storage buffer.
(2) Add the equilibration buffer and gently mix to ensure the beads are in an appropriate binding state.
(3) Repeat the washing step 1-2 times to fully activate the beads.
2. Sample Loading
(1) Add approximately 15 µL of the peptide sample directly into the magnetic bead suspension.
(2) Add 190 µL of 100% acetonitrile to achieve a final acetonitrile concentration of 95% in the tube.
(3) Gently vortex or briefly shake to ensure full contact between the sample and the beads.
(4) Incubate at room temperature for 5-10 minutes to facilitate efficient peptide binding (adjust incubation time as needed to optimize recovery).
3. Salt Removal and Washing
(1) Place the tube on the magnetic rack for 2 minutes and carefully discard the supernatant, avoiding bead aspiration.
(2) Wash the beads 2-3 times with wash buffer. After each wash, use the magnetic rack to separate beads and discard the supernatant.
(3) This step effectively removes salts, detergents, and other small-molecule contaminants from the sample.
4. SP2 Rinse
(1) Add 200 µL of 100% acetonitrile to fully cover the beads.
(2) Mix thoroughly by pipetting up and down to disperse the beads evenly, then let stand for 2 minutes.
(3) Place the tube back on the magnetic rack for 1 minute and discard the supernatant.
(4) Repeat the rinse step three times.
5. Peptide Elution
(1) Add 54 µL of 2% acetonitrile solution to the beads for elution.
(2) Gently tilt or invert the tube containing the beads for 30 seconds to dislodge beads from the tube walls.
(3) Use the magnetic rack to collect the beads and retrieve the supernatant, which contains the desalted peptide sample ready for downstream mass spectrometry analysis.
The entire procedure can be completed within 20-30 minutes without the need for additional equipment, significantly improving experimental efficiency while minimizing sample loss.
Features and Benefits
1. Efficient Desalting
Effectively removes high concentrations of salts (NaCl, KCl, ammonium formate, TFA, etc.) and small-molecule detergents (such as SDS, urea, DTT), enhancing mass spectrometry sensitivity and stability.
2. User-Friendly Operation
The entire purification process is completed using a magnetic rack without centrifugation, dialysis, or complex column chromatography.
3. High Recovery Rate
Optimized surface modification of magnetic beads ensures stable peptide binding, achieving recovery rates over 80%, making it ideal for low-concentration and precious samples.
4. Broad Compatibility
Suitable for various biological sample types, including protein digests and chemically synthesized peptides. Compatible with multiple mass spectrometry platforms such as LC-MS/MS and MALDI-TOF.
5. High-Throughput Ready
Adaptable to 96-well plates and automated liquid handling systems, supporting the needs of high-throughput mass spectrometry workflows.
6. Ready-to-Use
Pre-loaded with magnetic bead suspension and optimized buffers, the SP2 magnetic beads based peptide desalting kit provides a complete experimental solution with no need for additional reagent preparation, minimizing handling errors and improving experimental reproducibility.
Applications
1. Pre-treatment of Protein Digestion Products Prior to Mass Spectrometry
2. Proteomic Analysis of Biological Fluids Such as Plasma and Serum
3. Purification of Protein Digestion Products from Cell Lysates
4. Purification and Desalting of Synthetic Peptides
FAQs
Q1: What Types of Samples Are Compatible with the Kit?
A1: The SP2 magnetic beads based peptide desalting kit is broadly applicable to a wide range of peptide samples, including but not limited to protein digestion products (e.g., digests from trypsin, Lys-C, Glu-C, Asp-N), chemically synthesized peptides, cell lysates, and biological fluids such as plasma, serum, and urine.
Q2: What Types of Salts and Interfering Substances Can the Kit Remove?
A2: The SP2 magnetic beads based peptide desalting kit is specifically designed to remove common inorganic salts (NaCl, KCl, MgCl₂, CaCl₂), buffer salts (ammonium formate, phosphate, trifluoroacetic acid (TFA)), urea, SDS, DTT, β-mercaptoethanol and other small molecule interferences. These substances can compromise mass spectrometry sensitivity and stability. The SP2 magnetic beads efficiently eliminate these impurities, optimizing peptide samples for MS analysis and enhancing data quality.
Q3: What Is the Recovery Rate of the SP2 Magnetic Beads Based Peptide Desalting Kit? Is There Sample Loss?
A3: The kit uses optimized surface-modified magnetic beads to minimize nonspecific adsorption and ensure high peptide recovery. Internal validation has shown recovery rates exceeding 80%, significantly higher than traditional methods such as ultrafiltration, dialysis, or solid-phase extraction (SPE). It is particularly well-suited for recovering low-abundance peptides, minimizing sample loss and ensuring data accuracy and reproducibility.
Q4: Can the Eluted Sample Be Used Directly for Mass Spectrometry Analysis? Is Further Processing Required?
A4: The SP2 magnetic beads based peptide desalting kit includes an optimized elution buffer, allowing the eluted peptide samples to be directly used for LC-MS/MS or MALDI-TOF MS analysis without additional purification or drying steps. If further concentration is needed, researchers may choose to use a SpeedVac vacuum concentrator or lyophilization to accommodate lower-volume analysis requirements.
