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Desalting
Fast Clean-up of Proteins and Peptides Mr > 5 000
- Replace dialysis
- Desalt
- Buffer exchange
- Remove salts, low MW labels, co-factors, inhibitors, additives
 | Sample Volume (ml) | Use |
| Chromatography system | 2.5-15 ml | HiPrep 26/10 Desalting
sample volume: 2.5-15 ml
elution volume: 7.5-20 ml |
| 0.25-3 ml | HiTrap Desalting
sample volume: 0.25-3 ml |
| Syringe or peristaltic pump | 0.25-1.5 ml | HiTrap Desalting
sample volume: 0.25-1.5 ml*
elution volume: 1.0-2.0 ml |
| Manual (gravity feed) | 1.5-2.5 ml | PD-10 Desalting
sample volume: 1.5-2.5 ml
elution volume: 2.5-3.5 ml |
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Separation Principle
Gel filtration chromatography, using Sephadex G-25, is ideal for rapid sample clean-up of small or large volumes. The technique separates molecules on the basis of size and is used at laboratory and production scale, before, between or after chromatographic purification steps. Sample volumes of up to 30% of the total column volume are loaded. In a single step, the sample is desalted, exchanged into a new buffer, and low molecular weight materials, such as unwanted salts, are removed. The high speed and high volume capacity of this separation allows even large sample volumes to be processed rapidly and efficiently. The figure (below) shows a typical desalt/buffer exchange separation, with monitoring of UV and conductivity.
Samples are always diluted during a gel filtration separation.
Sample loads up to 30% of the total column volume give a separation with minimal sample dilution.
Larger sample volumes can be applied, but resolution will be reduced. |
| * 3.0 ml when using two HiTrap Desalting columns in series. |
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