Concentration, Desalting & Buffer Exchange

• Centrifugals: volumes <0.5 mL
• Centrifugals: volumes <4 mL
• Centrifugals: volumes <20 mL
• Centrifugals: volumes <70 mL
• 96-well format
• Static Concentrators
• Stirred Cells
• Tangential Flow Filtration

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Centrifugals: volumes <0.5 mL

Microcon^® Centrifugal Filter Units

The lab standard for sub-microliter volumes
Provides high recoveries (typically >95%) of even dilute (ng to µg/mL) protein solutions. Uses low-binding Ultracel-YM membrane with five cut-offs available: 3,000, 10,000, 30,000, 50,000 and 100,000 NMWL (Nominal Molecular Weight Limit).

Microcon^® Centrifugal Filter Units

The lab standard for sub-microliter volumes
- Solute recoveries typically >95%, ideal for dilute (ng/mL to µg/mL range) protein solutions
- Patented deadstop for reproducible concentrate volumes
- Inverted spin method of concentrate retrieval maximizes recovery
- Low-binding Ultracel-YM membrane
- Color coding indicates MW cut-off
- Convenient sample storage of filtrate or concentrated sample in standard microfuge collection tube
- Use in standard 1.5 mL tube fixed-angle rotors

Applications
- Concentrating and purifying proteins, antibodies and nucleic acids (alternative to EtOH precipitation)
- Desalting and buffer exchange
- Removal of primers, linkers and unincorporated label

Ultrafree^®-0.5 Centrifugal Filter Units

Units with high-flow Biomax membrane
- Highest sample flow and throughput
- Vertical membrane orientation to maximize effective filtration area
- Concentrate pocket allows for convenient access of sample with pipette
- Filtrate and concentrate retrieval in one spin
- Use in fixed-angle or swinging-bucket rotors

Applications
- Concentrating and desalting protein solutions
- Ideal for highly concentrated samples such as conditioned media, lysates, or complex mixtures of macromolecules

• Centrifugals: volumes <4 mL

Amicon^® Ultra-4 Centrifugal Filter Units

The premier devices for concentrating 1–4 mL
- High recovery Ultracel regenerated cellulose membrane in a range of molecular weight cut-offs
- High retentate recovery of >90%
- Vertical membrane reduces concentration polarization for ultra-fast spin times (as fast as 5 minutes)
- Heat-sealed membrane minimizes downstream extractables
- 100% integrity tested for reliable performance
- Convenient sample monitoring with translucent housing and volume gradations
- Direct pipettor sample access eliminates processing step to recover concentrate
- High concentration factors of 80–100X

Applications
- Concentration of biological samples containing antigens, antibodies, enzymes, nucleic acids, or microorganisms
- Purification of macromolecular components found in tissue culture extracts or cell lysates
- Concentration of dilute or pre-purified proteins from column eluents
- Desalting and buffer exchange

Amicon Ultra-15 Centrifugal Filter Units

The premier devices for concentrating <15 mL
- High recovery Ultracel regenerated cellulose membrane in a range of molecular weight cut-offs
- High retentate recovery of >90%
- Vertical membrane reduces concentration polarization for ultra-fast spin times (as fast as 10–15 minutes)
- Heat-sealed membrane minimizes downstream extractables
- 100% integrity tested for reliable performance
- Convenient sample monitoring with translucent housing and volume gradations
- Direct pipettor sample access eliminates processing step to recover concentrate
- High concentration factors of 80–100X

Centrifugals: volumes <20 mL

Centriprep^® Centrifugal Filter Units

For processing high solute samples
- For use with high solute samples
- Unique inverse flow mode of operation with large deadstop
- Fast sample processing
- Available with Ultracel-YM membranes: 3,000, 10,000, 30,000 and 50,000 kDa NMWL (Nominal Molecular Weight Limit)
- Fits standard swinging-bucket rotor for 50 mL tubes

Applications
- Concentrate and purify particle-laden solutions or high concentrations
- Separate low MW solutes from fermentation broths, cell culture media, cell lysates

Centrifugals: volumes <70 mL

96-well format

MultiScreen^® Filter Plate with Ultracel^®-10 Membrane

Concentration and purification of biological solutions

Versatile Operation
MultiScreen filter plate with Ultracel-10 membrane allows for processing and collection of sample volumes from 50 to 500 µL. They are compatible with a range of standard receiver 96-well microtiter plates including 300 µL, 700 µL deep well and 150 µL conical well.

MultiScreen filter plate with Ultracel-10 membrane is ideal for applications including protein concentration and desalting prior to validation or screening assays. They are able to remove large molecular weight proteins prior to instrument analysis.

Minicon^® and Miniplus^® Concentrators

For clinical chemistry
- Concentrate urine and cerebrospinal fluid to intensify proteins that indicate abnormal or pathological states prior to analysis by electrophoresis or immunoelectrophoresis (e.g., Bence Jones proteins in urine)
- Static concentrator, requiring no accessories
- Absorbent pulls solvent and salts through ultrafilter, concentrating sample

Static Concentrators

Stirred Cells

High-Output Stirred Cell

For 50 mL to 2 L
- Large membrane area
- Built-in stirring motor (detachable under sterile conditions)
- Smooth stirring control
- For 150 mm disc filters

Solvent-Resistant Stirred Cells

For volumes up to 75 or 300 mL
For applications requiring compatibility with solvents, this Millipore stirred cell is available in two sizes. Certain aldehydes, ketones (e. g., acetone) and aliphatic ethers/esters may reduce the life of the fluorocarbon O-rings. Please contact Millipore for more information.

- Borosilicate glass cylinder and PTFE components for broad compatibility
- Autoclavable with membrane in-place
- Top plate opening provides access to contents without dismantling
- Few components, so it's easy to clean and assemble
- For 47 or 76 mm disc filters