Seplife® DX 25/40 Dextran-Based Size Exclusion Chromatography Resin

Dextran-Based Chromatography Resins

Appearance: White spherical beads
Type: Gel Filtration
Matrix: Crossed linked dextran
Particle size (dry, µm): 20-80
Swelling property (ml/g): 4.5-6.5
pH stability: 3-10 (operational), 2-13 (CIP)
Chemical Stability: Stable in all common aqueous buffers; 1M sodium hydroxide; 8M urea; 6M guanidine hydrochloride; 70% ethanol.
Flow rate* (cm/h): max. 180
Shipped as: dry

*Testing conditions: Chromatography column 16mm×200mm; column bed height 15cm; temperature 25°C; mobile phase 0.1M NaCl

Product pretreatment Dextran gel filtration chromatography media is supplied as a dry powder, and must be swelled in excess buffer solution before use (swell overnight at room temperature, or in boiling water for 1 hour.) Avoid magnetic stirring, or stirring with overhead stirrer or glass rod that may cause damage to the chromatography media. After swelling, adjust with buffer to form a thick slurry, about 75% (volume percentage), and then degas if possible.

Column packing
Column loading should be done according to standard operating procedures. Before packing the column, it is necessary to ensure that each material is at its working temperature, and the temperature of the buffer and media must be the same (room temperature). Dextran gel filtration chromatography media comply with Darcy's law, if the flow rate is doubled, the column pressure will also be doubled.

Equilibration
Equilibrate the column with an appropriate 2-5 column volume buffer. Ensure the conductivity and pH of the effluent are the same as the equilibration buffer.

Sample feeding
1) The separation of sample components by the media is carried out according to the molecular size of the components, and the ones with the larger molecular size flow out first.
2)The sample feeding for gel filtration is generally 5% of the column bed in volume, and we recommend that the initial sample feeding be controlled at 1-2% of the bed volume, which can be adjusted depending on the separation situation. When desalting, the sample feeding can reach 20% of the column bed volume. The selection of column height is also related to the separation requirements. The column height should be controlled below 40 cm. Too high a gel layer will cause greater back pressure and should be avoided as much as possible.
Difficult-to-separate substances must have a certain column height and flow rate control. A 5:1 height-to-diameter ratio for desalting is recommended.
3) Samples with particulates and precipitate should be filtered or centrifuged before the chromatography purification. The viscosity of the sample should not be too high, otherwise the separation efficiency will be reduced.

Elution
Elution can be done with salt-free water or with equilibration buffer as eluent, depending on the scope of the experiment. Complete separation can be achieved by adding NaCl to the equilibration buffer for gradient elution, or salt gradient elution.

Cleaning-in-place (CIP)
After the media is used 10 times, a CIP is performed to remove the precipitated and stubborn residual proteins in the column bed. The method is to backwash with 4 bed volumes of 1M NaOH at 40cm/h, and then regenerate with at least 3 bed volumes of equilibration buffer.

Storage
Seplife®DX 25/40 dry powder should be stored in a dry, ventilated and clean place at 4-30°C; the hydrated media should be stored in 20% ethanol solution. Avoid contact with oxidants and do not freeze.