
Products
SHBC provides colored microspheres, fluorescent microspheres, magnetic beads, silica microspheres, chromatography packing microspheres and biological reagents for diagnostic assay development, nucleic acid extraction, protein purification and separation applications.
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TopGF G-25 SF
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SHBC
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50µm
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25g 100g 500g 1kg 5kg 25kg
50 μm Dextran Gel Filtration Media G-25 SF
SHBC TopGF G-25 SF is a superfine dextran gel filtration medium with a nominal particle size of 50 μm.
It is designed for protein desalting, buffer exchange and removal of salts or other low-molecular-weight substances from antibodies, antigens, enzymes and protein conjugates.
TopGF G-25 SF is suitable for immunoassay development, biomolecule preparation and scalable biotechnology production.
TopGF G-25 SF Technical Specifications
Property | Specification |
|---|---|
Product Name | Dextran Gel Filtration Media G-25 SF |
Product Code | TopGF G-25 SF |
Matrix | Cross-Linked Dextran |
Nominal Particle Size | 50 μm |
Particle Grade | Superfine |
Separation Mode | Size Exclusion Chromatography |
Main Function | Desalting and Buffer Exchange |
Brand | SHBC |
Manufacturer | Shanghai SanYu Biotechnology Co., Ltd. |
How Does TopGF G-25 SF Work?
TopGF G-25 SF separates molecules according to their effective molecular size.
Large biomolecules are excluded from most pores and pass through the column first. Salts, free dyes and other small molecules enter the porous matrix, travel through a longer path and elute later.
The target biomolecule does not need to bind to the matrix, allowing rapid group separation and buffer exchange. ages of TopGF G-25 SF
Cross-linked dextran matrix
Nominal 50 μm particle size
Superfine particle grade
Efficient protein desalting
Rapid buffer exchange
Removal of small-molecule impurities
High separation efficiency
Separation without ligand binding
Suitable for antibodies and proteins
Available for research and bulk supply
Why Choose the Superfine Grade?
TopGF G-25 SF uses smaller particles than Fine, Medium and Coarse grades.
Potential advantages include:
More uniform packed beds
Improved separation efficiency
Better fraction definition
Efficient removal of salts and free reagents
Suitable laboratory-scale purification
Suitable for process-development columns
Smaller particles generally improve gel filtration resolution but may increase flow resistance. Column dimensions, pressure and flow rate should therefore be optimized. y Manufacturing Applications
Antibody Desalting
TopGF G-25 SF can be evaluated for removing salts and small buffer components from antibody preparations.
Typical applications include:
Desalting after antibody purification
Removal of ammonium sulfate
Removal of reducing agents
Cleanup after antibody concentration
Preparation before antibody labeling
Preparation before magnetic-bead coupling
Antibody Buffer Exchange
Antibodies can be transferred into a selected coupling, assay or storage buffer before:
Epoxy magnetic-bead coupling
Carboxyl magnetic-bead coupling
Fluorescent labeling
Enzyme conjugation
Biotinylation
Chemiluminescent labeling
Immunoassay formulation
Antigen and Protein Preparation
TopGF G-25 SF can also be evaluated for:
Antigen desalting
Recombinant protein buffer exchange
Enzyme formulation
Protein cleanup
Removal of small reaction components
Sample preparation before further chromatography
Removal of Free Labeling Reagents
TopGF G-25 SF may be used to separate labeled proteins from smaller unreacted substances, including:
Free fluorescent dyes
Free biotin reagents
Unreacted labeling reagents
Reducing agents
Buffer salts
Small reaction by-products
G-25 Superfine media are commonly used for desalting, buffer exchange and cleanup of biological samples. system should be validated according to the molecular sizes of the target conjugate and free reagent.
Suitable Samples
TopGF G-25 SF can be evaluated with:
Monoclonal antibodies
Polyclonal antibodies
Recombinant proteins
Diagnostic antigens
Enzymes
Protein conjugates
Labeled antibodies
Labeled antigens
Other water-soluble biomolecules
Performance depends on molecular size, sample concentration, viscosity, loading volume and column conditions.
General Operating Workflow
1. Hydrate the Medium
Hydrate the dry medium completely using purified water or the selected buffer.
Allow sufficient time for uniform swelling before column packing.
2. Prepare a Uniform Slurry
Mix the hydrated medium gently to create a uniform slurry.
Avoid excessive air bubbles and strong mechanical shear.
3. Pack the Column
Transfer the slurry into a suitable chromatography column and allow the bed to settle evenly.
Avoid cracks, channels and trapped air.
4. Equilibrate the Column
Wash the packed bed with the target buffer until the outlet conditions are stable.
5. Load the Sample
Apply the sample evenly without disturbing the packed-bed surface.
6. Elute the Biomolecule
Elute using the target buffer. Larger biomolecules normally elute before salts and other small molecules.
7. Collect and Evaluate
Collect the target fraction and evaluate:
Protein concentration
Conductivity
Biomolecule recovery
Buffer composition
Purity
Biological activity
Immunoassay performance
Factors Affecting Separation Performance
Important factors include:
Sample volume
Bed volume
Column dimensions
Packed-bed quality
Flow rate
Protein concentration
Sample viscosity
Molecular-size difference
Buffer composition
Fraction collection volume
The sample-to-bed-volume ratio should be optimized to balance desalting efficiency, biomolecule recovery and sample dilution.
Column Packing Recommendations
For consistent results:
Hydrate the medium completely.
Prepare a uniform slurry.
Remove trapped air before packing.
Maintain a level bed surface.
Avoid excessive bed compression.
Prevent the packed bed from drying.
Confirm stable flow before sample loading.
Check the bed for cracks or channels.
Superfine media require careful packing because smaller particles create greater flow resistance than larger grades.
Process Scale-Up
When transferring the process from laboratory testing to production, maintain consistent:
Bed height
Sample-to-bed-volume ratio
Linear flow velocity
Buffer composition
Sample concentration
Fraction collection strategy
Cleaning procedure
Product acceptance criteria
G-25 media are established for industrial desalting and buffer exchange because they can remove small contaminants and transfer biomolecules into a new buffer in one processing step. SF Grade Comparison
Feature | G-25 SF | G-25 F | G-25 M | G-25 C |
|---|---|---|---|---|
Nominal Particle Size | 50 μm | 90 μm | 140 μm | 320 μm |
Particle Grade | Superfine | Fine | Medium | Coarse |
Separation Efficiency | Highest | High | Balanced | Moderate |
Flow Resistance | Highest | High | Moderate | Lowest |
Processing Speed | Lower | Moderate | Balanced | Faster |
Main Selection | Improved fraction definition | Efficient desalting | General processing | Rapid bulk processing |
Choose G-25 SF when separation efficiency is the main priority. Choose larger grades when faster flow and lower pressure are more important.
TopGF G-25 SF vs. Dialysis
Feature | TopGF G-25 SF | Dialysis |
|---|---|---|
Separation Method | Size-exclusion column | Membrane diffusion |
Processing Time | Relatively rapid | Usually longer |
Buffer Exchange | Completed during elution | Requires external buffer changes |
Sample Collection | Column fractions | Dialysis container |
Process Control | Controlled bed and flow | Controlled by membrane and time |
Typical Use | Rapid desalting and cleanup | Equilibrium-based buffer exchange |
Size-exclusion desalting provides a rapid alternative to dialysis for removing salts and other small molecules from protein samples. ntrol for Bulk Production
Recommended evaluation items include:
Particle-size consistency
Swelling consistency
Packed-bed uniformity
Flow performance
Desalting efficiency
Protein recovery
Conductivity reduction
Sample dilution
Lot-to-lot consistency
Storage stability
Why Choose SHBC TopGF G-25 SF?
Nominal 50 μm superfine particles
Cross-linked dextran matrix
Designed for desalting and buffer exchange
Suitable for antibodies, antigens and proteins
Supports immunoassay reagent development
Samples available for evaluation
Stable batch manufacturing
Bulk packaging options
Scalable production supply
Technical support for grade selection
Storage and Handling
Store TopGF G-25 SF according to the product label and technical documentation.
Recommended practices:
Keep unused dry medium tightly sealed.
Protect the product from moisture and contamination.
Use clean water, buffers and equipment.
Avoid strong mechanical damage to hydrated particles.
Do not allow the packed column to dry.
Use a validated storage solution for hydrated media.
Review the SDS before use.
Frequently Asked Questions
What is TopGF G-25 SF?
TopGF G-25 SF is a superfine cross-linked dextran gel filtration medium used for desalting, buffer exchange and group separation.
What is the particle size?
The nominal particle size is 50 μm.
What is its main application?
Its main applications are antibody and protein desalting, buffer exchange and removal of low-molecular-weight substances.
Can it purify antibodies directly?
It can desalt antibodies and replace their buffer. It does not replace affinity chromatography for selective antibody capture.
Can it be used before magnetic-bead coupling?
Yes. It can be evaluated for transferring antibodies or proteins into a compatible coupling buffer.
Can it remove free fluorescent dyes?
It may remove free dyes when they are sufficiently smaller than the labeled protein. Each labeling process should be validated.
Can it remove salts from proteins?
Yes. Under suitable operating conditions, proteins elute before salts and other small molecules.
Why select the Superfine grade?
The smaller particle size can provide improved separation efficiency and better fraction definition compared with larger-particle grades.
Does the Superfine grade have higher flow resistance?
Yes. Smaller particles generally increase flow resistance, so the column and flow conditions should be optimized.
Is TopGF G-25 SF suitable for high-resolution protein fractionation?
It is primarily intended for group separation, desalting and buffer exchange rather than detailed molecular-weight fractionation.
Is process optimization required?
Yes. Sample volume, bed volume, flow rate, buffer and fraction collection should be optimized for each application.
Can SHBC supply bulk quantities?
Yes. SHBC supports sample evaluation and bulk supply for research laboratories, immunoassay developers and biotechnology manufacturers.
Request TopGF G-25 SF Samples
Contact Shanghai SanYu Biotechnology Co., Ltd. for samples, technical documentation and bulk quotations.
Please provide:
Target biomolecule
Current buffer
Required new buffer
Sample volume
Protein concentration
Column dimensions
Required processing capacity
Estimated annual demand
TopGF G-25 SF is supplied for research and process development. Customers should validate the medium for their final manufacturing or diagnostic application.


