Amicon® Ultra centrifugal devices are ideal for removal or exchange of salts, sugars, nucleotides, and non-aqueous solvents, as well as other materials of low molecular weight. They also serve to separate free from bound species.
Amicon® Ultra centrifugal concentrators provide fast, convenient, high-recovery alternatives to dialysis and ethanol precipitation. Sample dilution, often associated with spin columns, is not a problem. Salt transfer across the membrane is efficient and independent of microsolute concentration or size.
The removal of salts or the exchange of buffers can be accomplished in the Amicon® Ultra-0.5, 2mL, 4mL and 15mL devices by concentrating the sample, then reconstituting the concentrate to the original sample volume with any desired solvent. The process of "washing out" can be repeated until the concentration of the contaminating microsolute has been sufficiently reduced. See the Amicon® Ultra-0.5 mL diafiltration example below.
- Fast: buffer exchange in as few as two spins
- Efficient: requires minimal volume of exchange buffer, easily contained in reservoir
- Easy to use: simply load your sample with standard pipette
- Enables simultaneous concentrating and desalting
Efficient diafiltration: Follow these steps to use an Amicon® Ultra 0.5 mL centrifugal filter to concentrate a protein sample 10X while also gradually reducing the salt concentration by 9X.