Intro

Centrifuge filters are very useful for small volume sample filtration.  Designed for use in centrifuges, the filter units consist of a sample chamber and a receiver tube.  Various membranes are available for bacteria removal, particle removal, HPLC sample preparation, removal of cells from media and DNA removal from agarose or acrylamide gels.  The tube has a marking area and is graduated.  A cap serves the dual purpose of capping the sample chamber during the centrifugation and the receiver tube after the sample chamber has been removed.

• Centrifugal force, temperature and sample volume, concentration and viscosity affect filtration rate. Optimize centrifugal time for each application. 
• Storage: Upon receipt store at room temperature. Product shipped at ambient temperature. 
• Provided non-sterile. May be sanitized by filtering 70% ethanol through the device prior to use.

 

Membrane Selection Guide

All filters are available with many different membrane types:

Nylon

Nylon membrane filters are fast becoming the "standard" filter material due to their wide chemical compatibility range and naturally hydrophilic characteristics. Nylon filters can be used to filter all aqueous and the majority of solvent solutions.

• Naturally hydrophilic
• Wide chemical compatibility range
• Strength and dimensional stability
• Extremely low extractables

Applications

• Sterilization, clarification of aqueous and organic solvent solutions
• HPLC sample preparation

 

Polypropylene

Polypropylene membrane filters are composed of pure polypropylene with absolute pore size ratings. These filters offer broad chemical compatibility allowing its use with aqueous and organic solvent samples. The polypropylene filter has extremely low extractable levels designed to provide accurate, consistent analysis results for sensitive ion chromatography applications while prolonging column life. Polypropylene filter is the preferred filter membrane for HPLC applications where the detection levels are below 230 nm. The filters also exhibit negligible protein binding which is essential for maximum sample recovery of critical, small volume protein samples.

• Naturally hydrophilic
• Wide chemical compatibility range
• Strength and dimensional stability
• Extremely low extractables

Applications

• Sterilization, clarification of aqueous and organic solvent solutions
• HPLC sample preparation

CA (Cellulose Acetate)

CA (Cellulose Acetate) membrane filters are composed of pure cellulose acetate modified to offer researchers the lowest binding filters available. Due to the extremely low binding characteristics, these filters provide higher throughputs than competitive offerings and reduce filter changes when filtering proteinaceous solutions. Because of their unique strength and extremely low binding characteristics, CA (Cellulose Acetate) filters are ideal for protein and enzyme filtrations, tissue culture media sterilization, cold sterilization, biological fluid filtration and other filtration applications where maximum recovery of proteins is critical.

CA (Cellulose Acetate) membranes are manufactured using a unique impregnation process that is internally supported by an inert polyester web eliminates cracking, tearing, breaking and distortion when handled or creased. Each filter has unequalled dimensional stability after autoclaving or steam sterilizing and is completely unaffected by temperatures up to 135°C (275°F). The exclusive impregnation process results in an acetate filter which has a burst strength of 130 psi, uniform pore size and consistent flow rates for reliable performance.

• Lowest binding material available
• Hydrophilic
• High throughput
• Strength and dimension stability
• Uniform pore structure

Applications

• Protein and enzyme filtration, sterilization
• Biological fluid filtration sterilization
• Tissue culture media sterilization

PTFE (Teflon®)

PTFE (Teflon®) polytetrafluoroethylene membrane consists of a pure PTFE laminated to a polypropylene support for improved durability and easy handling. These filters are chemically compatible with strong acids and most aggressive solvents such as alcohols. Laminated PTFE filters can also be used to filter aqueous solutions when prewetted with methanol.

• Naturally hydrophobic
• Compatible with strong acids and aggressive solutions
• Improved durability and handling

Applications

• Filtration of strong acids and aggressive solutions
• Venting applications
• Phase separations
• Aerosol samplings

Nitrocellulose

Nitrocellulose - Mixed Esters (ME) - unsupported filters are composed of a mixture of inert cellulose nitrate and cellulose acetate polymers. The uniform microporous structure of these filters provides the fastest flow rates and highest throughputs available in a membrane filter. Because they are biologically inert, Nitrocellulose filters are ideal for a wide range of clarification, sterilization, and analytical applications such as: microbiological analysis, clarification or sterilization of aqueous solutions, industrial hygiene applications, silt density index (SDI - 0.45µm, 47mm) and particulate-matter analysis.

• Hydrophilic for aqueous clarification and particulate capture
• Consistent high flow rate for faster filtration
• Uniform pore structure for selectivity
• Hydrophilic, inert cellulose nitrate
• High binding capacity
• Manufactured thickness within 10 microns

Applications

• Aqueous filtration
• Microbiological analysis
• Sterility testing
• Gravimetric analysis with ashing technique
• Particulate analysis
• Black - food and beverage

PES (Polyethersulfone)

PES (polyethersulfone) filters are inert which provide extremely low extractable levels in critical sterilization applications such as protein and enzyme filtrations, tissue culture media sterilization, cold sterilization, biological fluid filtration and other sterilization applications where maximum throughputs and fast flow rates are the critical factors.

• Very Low Protein Binding
• Fast Flow Rates
• Low Extractables
• Wide Chemical Compatibility Range
• Strength and Dimensional Stability
• Autoclavable

Applications

• Protein and enzyme filtration sterilization
• Biological fluid filtration sterilization
• Tissue culture media sterilization
• Pharmaceutical sterilizing filtration
• Environmental water studies

PVDF MEMBRANES

These hydrophilic, extremely low extractable/protein binding, PVDF membrane filters provide high flow rates and throughputs for aggressive, solvent-based mobile phase applications, biological sterilization/clarification, and HPLC/analytical sample preparation.

These PVDF membranes do not require the use of wetting agents, transmitting negligible extractables and increasing sample purity during sterilization or clarification procedures. Because of their exceptionally low protein binding levels--even lower than similar nylon, nitrocellulose, and PTFE membranes--our PVDF filters are well-utilized in the preparation of proteinacious solutions for chromatography and other instrumental analyses. Broad chemical compatibility allows these PVDF filters to accommodate a wide range of applications--especially those requiring high flow rates/throughput--including aggressive/non-aggressive acids, alcohols, and solvents in mobile phase. Our versatile PVDF membrane filters are available with pore sizes of either 0.22 or 0.45 μm; however, the 0.22 μm pore size is preferred for the removal of uHPLC contaminants most likely plug columns and damage analytical results.

Applications

• HPLC solutions filtration
• GC sample prep/clean up and
• Purifying protein-based samples with high non-specific binding
• Aggressive and non-aggressive solvents

Regenerated Cellulose Membrane

Product Information

Regenerated cellulose membrane filters are microporous cellulose acetate filters made without wetting agents. RC offers low extractables and wide compatibility in both organic and aqueous media.

Regenerated cellulose membrane filters have s broad solvent compatibility, and they contribute very low extractable material in a wide variety of sample solvents. Thus, they are appropriate for sample preparation in many applications.

• Spontaneous wetting with very good wet strength
• Chemical resistance suitable for a wide range of aqueous and organic media
• Mechanically stable with low protein binding
• Low extractable levels to minimize sample contamination
• Can be sterilized by all common methods

Applications

The very low adsorption membranes are hydrophilic, solvent-resistant (pH 3-12) and therefore suited for the particle removal from solvents. The membrane is asymmetric and reinforced with nonwoven cellulose. They are available in two pore sizes: 0.45 µm and 0.2 µm.