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Laboratory Concentration Devices

Downstream analyses require that proteins, nucleic acids, virus particles, and other biomolecules are solubilized in their native form at an appropriate concentration. Ultrafiltration methods can be used to gently and efficiently concentrate biological or environmental samples by removing excess liquid or buffer. A variety of ultrafiltration devices are available to rapidly concentrate proteins and other biomolecules with high recovery.

  • Centrifugal filters for concentrating proteins, antibodies, and other biomolecules (< 0.5 mL – 70 mL volumes)
  • Stirred cells for concentrating large volume protein, antibody, biological, and environmental samples (50 mL – 800 mL volumes)
  • Clinical sample concentrators for concentrating serum, plasma, urine, and other clinical samples



Centrifugal Filtration Devices for Protein Concentration

Centrifugal ultrafiltration devices use centrifugal force to gently drive solutes and liquids through a semi-permeable membrane for quick concentration of proteins, antibodies, and other biomolecules in small to medium volume samples.

Microcon® Centrifugal Filters

Simply and efficiently concentrate and desalt solutions of peptides, proteins, and genomic DNA with low-binding Ultracel® regenerated cellulose (RC) or Biomax® PES membranes using any centrifuge that can accept 1.5 mL tubes.

  • ≤ 0.5 mL sample volumes
  • Typical recoveries of >95%, even for dilute solutions
  • Reverse spin to maximize recovery, even in the smallest samples
  • Convenient storage of filtrate or concentrated sample in standard microfuge tube
  • Concentration factors up to 100X

Ultrafree® Centrifugal Filters

Ultrafree®-MC and Ultrafree®-CL centrifugal filters remove particles and precipitates from aqueous and some solvent-based samples. These fast filtration units provide highly reproducible performance for sample recovery.

  • 0.5 mL – 2 mL sample volumes
  • Clarification, filtration, and sterilization of protein and nucleic acid solutions
  • High recovery Durapore® (PVDF) and hydrophilic PTFE membranes
  • Five different pore sizes from 0.1 to 5.0 µm
  • Sterile and non-sterile options
  • Fast filtration and highly reproducible performance

Amicon® Ultra Centrifugal Protein Concentrators

Amicon® Ultra Centrifugal filters provide fast sample processing and promote high sample recoveries, even in dilute samples, through ultrafiltration. The unique features of the Amicon® Ultra centrifugal filters give you the fastest, most efficient concentration for sensitive downstream applications.

  • 0.5 mL - 15 mL sample volumes
  • >90% sample recovery with low binding Ultracel® regenerated cellulose (RC) membrane and polypropylene housing
  • Fast processing times (10-30 minutes)
  • Deadstop technology prevents spinning to dryness
  • Reverse spin enables you to maximize protein recovery, especially with small dilute samples, without introducing pipetting errors

Centricon® Plus-70 Centrifugal Filters

The Centricon® Plus-70 centrifugal filter is designed for rapid processing of aqueous biological solutions in volumes ranging from 15 to 70 mL. Centricon® filters concentrate most 70 mL solutions down to 350 μL in as little as 25 minutes. Samples are typically concentrated in the 50X to 200X range, depending on the sample type and starting sample volume. These units are a convenient alternative to dialysis, lyophilization, or precipitation techniques.

  • 15 mL – 70 mL sample volumes
  • >90% typical recovery
  • Low hold-up volume
  • Polypropylene housing minimizes binding
  • True dead stop prevents spinning to dryness
  • Concentrating and desalting chromatography column eluates
  • Concentrating monoclonal antibodies
  • Concentrating proteins or viruses from culture supernatants
  • Clarifying tissue homogenates and cell lysates

Stirred Cells for Large Sample Volume Concentration

Stirred cells use pressurized ultrafiltration (pUF) at high flow rates to process large sample volumes for rapid concentration of proteins, virus particles, and other biological and environmental samples.

Amicon® Stirred Cells

Amicon® stirred cells provide high flow rates with solutions up to 10% macrosolute concentration and are capable of rapid concentration or salt removal followed by concentration in the same unit. For protein concentration, gas pressure is applied directly to ultrafiltration cell. Solutes above the membrane’s nominal molecular weight cut-off (NMWCO) are retained in cell, while water and solutes below the cut-off pass into the filtrate and out of cell.

  • Three different sizes to handle volumes from 50 mL to 400 mL, with an optional external 800 mL reservoir for expanded capacity
  • Use with Ultracel® RC (regenerated cellulose), Biomax® PES (polyethersulfone), or Durapore® PVDF membranes ultrafiltration discs
  • Concentrate, diafilter, and exchange buffers for macromolecule solutions including proteins, enzymes, antibodies and viruses
  • Gentle magnetic stirring minimizes concentration polarization and shear denaturation.
  • All stirred cells can be autoclaved
  • High flow rates with solutions up to 10% macrosolute concentration

Solvent-Resistant Stirred Cells

The Millipore® Solvent Resistant Stirred Cell is constructed from stainless steel and borosilicate glass for applications requiring compatibility with solvents. It is designed to offer a rapid and efficient method for concentrating or desalting samples of up to 300 mL under high pressure.

  • 75 mL - 300 mL sample volumes
  • Protein desalting, purification, and concentration applications involving organic solvents
  • 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 for easy cleaning and assembly

Clinical Sample Concentration

Centrifree® Centrifugal Filters

The Centrifree® filter was designed with the clinical laboratory in mind. These devices rapidly and efficiently separate free from protein-bound microsolute in small volumes (0.15–1.0 mL) of serum, plasma, and other biological samples using ultrafiltration. Accurate partitioning occurs in minutes without dilution, change in physiologic pH, ion composition, or unbound microsolute concentration. These devices contain low-adsorptive hydrophilic membranes and O-rings without plasticizers to ensure excellent recovery.

  • 0.15 mL – 1.0 mL sample volumes
  • Separation of free from bound microsolute in serum, plasma, and other biological samples
  • Determine free therapeutic drugs, testosterone, thyroxin, etc.
  • Binding studies
  • New drug investigations
  • Deproteinization

Minicon® Static Concentrators for Clinical Samples

Minicon® concentrators are non-sterile, disposable, multiwell ultrafiltration devices designed for concentrating macromolecules in clinical specimens such as urine, cerebrospinal fluid (CSF) or other biological solutions. The concentrators, which require no additional equipment and can be operated unattended, are used by researchers and clinical laboratories worldwide as a preparatory step to increase the sensitivity of subsequent tests.

  • 2.5 mL – 5 mL clinical sample volumes
  • 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



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