SUNRESIN
Stock Code 300487
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Sephadex™ G-25 is a widely used gel filtration resin for desalting, buffer exchange, and biomolecule purification in biochemical research and industrial applications. Composed of cross-linked dextran, it is available in different particle sizes, including Fine and Medium, each suited to specific needs. This article compares Sephadex™ G-25 Fine and Medium to help you decide which is best for your application.
Sephadex™ G-25 is a gel filtration medium designed for size-exclusion chromatography, separating molecules based on size. It has a fractionation range of 1,000–5,000 Da for globular proteins and 100–5,000 Da for dextrans, making it ideal for desalting and buffer exchange. The resin’s hydrophilic matrix minimizes nonspecific adsorption, ensuring high recovery rates for proteins and nucleic acids.
Particle Size: 20–80 µm (smaller beads)
Swelling Capacity: ~4–6 mL/g (higher swelling due to smaller beads)
Efficiency: Higher resolution due to shorter diffusion distances
Flow Rate: Slower, due to smaller bead size and higher backpressure
Laboratory-Scale Separations: Ideal for small-scale preparative work, such as desalting proteins or nucleic acids in research settings.
High-Resolution Needs: Suited for applications requiring precise separation of molecules with similar sizes, e.g., removing unreacted dye from labeled proteins.
Prepacked Columns: Commonly used in HiPrep™ 26/10 Desalting or HiTrap™ Desalting columns for convenient, high-efficiency desalting.
Higher resolution for better separation of closely sized molecules
Excellent for small-scale, high-precision lab work
Minimal sample dilution with high recovery rates
Slower flow rates due to smaller particle size
Higher operating pressure, requiring careful column packing
Longer run times compared to Medium grade
Particle Size: 50–150 µm (larger beads)
Swelling Capacity: ~4–6 mL/g (slightly lower swelling than Fine)
Efficiency: Lower resolution but faster flow rates
Flow Rate: Higher, suitable for large-scale separations with lower backpressure
Industrial Applications: Preferred for large-scale group separations, such as desalting or buffer exchange in bioprocessing.
High-Throughput Needs: Used when faster processing is prioritized over resolution, e.g., separating radioiodinated proteins from free iodine.
Large Columns: Ideal for columns requiring high flow rates and low operating pressures.
Faster flow rates, reducing processing time
Lower backpressure, easier to pack and operate in large columns
Cost-effective for large-scale applications
Lower resolution compared to Fine grade
Less suitable for separating molecules with similar molecular weights
Resolution vs. Speed: Sephadex™ G-25 Fine offers higher resolution for precise separations in lab-scale experiments, while Medium is better for faster, large-scale processes where resolution is less critical.
Column Size and Flow Rate: Fine is suited for smaller columns with slower flow rates, while Medium supports larger columns with higher flow rates, obeying Darcy’s Law for rigid spheres.
Application Scale: For routine lab work, Fine is preferred; for industrial bioprocessing, Medium is more practical.
Sample Type: Both are effective for desalting and buffer exchange, but Fine excels in applications requiring high purity, such as preparing samples for mass spectrometry or NMR.
Swelling and Packing: Both grades are supplied as dry powder and must be swollen in buffer (pH 2–13) before use. Use a boiling water bath to accelerate swelling, but avoid magnetic stirrers to prevent bead damage. Aim for a 75% settled gel suspension.
Column Performance: Monitor Height Equivalent to a Theoretical Plate (HETP). For G-25, HETP values above 0.05 cm may indicate poor packing, affecting separation.
Buffer Compatibility: Both grades are stable in common buffers, urea (8 M), guanidine hydrochloride (6 M), and lower alcohols (<25% v/v). Avoid prolonged exposure to pH <2 or >13.
Choose Sephadex™ G-25 Fine for laboratory-scale experiments requiring high resolution, such as purifying proteins or nucleic acids for downstream analyses like mass spectrometry. Its smaller beads provide better separation but require slower flow rates.
Choose Sephadex™ G-25 Medium for industrial-scale desalting or buffer exchange where speed and throughput are priorities. Its larger beads allow faster flow rates and lower backpressure, ideal for bioprocessing.
Sephadex™ G-25 Fine and Medium are both excellent gel filtration media, but their suitability depends on your application. Fine is best for high-resolution, small-scale lab work, while Medium excels in high-throughput, large-scale processes. By considering your resolution needs, column size, and processing scale, you can select the right grade—or explore alternatives like those from Sunresin—to optimize your chromatography results.
Contact suppliers like Sunresin New Materials Co. Ltd. for Sephadex™ G-25 or alternative chromatography resins tailored to your needs.
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