Membrane Selection Guide by Application

Particulate analysis

PCTE or PETE

• Samples are collected in one plane, in focus.
• Superior morphologic resolution.
• No clearing of membrane for most applications.
• Simpler slide preparation.
• Uniform sample deposition.
• Particles can be fractionated by discrete sizes.

Bromine and Chlorine

Silver

0.45 µm

• NIOSH Method 6011

Polyaromatic hydrocarbons

Silver

• Reusable for economy

Silica (crystalline), zinc oxide, cotton dust, chromic acid mist, oil mist, lead sulfide, nuisance dust, carbon black

PVC

0.8 and 5.0 µm

• Silica and contaminant free.
• NIOSH Methods 5000, 7505, 0500, 0600, 7601, 7502, 7500, 7602.

Cadmium, cyanides, lead, quartz in coal dust, welding and brazing fu

MCE (Mixed Cellulose Esters)

0.8 µm

• NIOSH Methods 7048, 7904, 7082, 7602, 7200

Trace element

PETE/PCTE for aerosols

0.2 – 8.0 µm

• Low trace elements contamination in special aerosol membranes.

Quartz/Silica

Silver

• NIOSH Methods S315, OML.

Zinc oxide fumes

Silver

• NIOSH Method S316.

Activation analysis

PCTE or PETE

• Minimal absorption of beta radiation.
• Low membrane trace elements.

Adsorbable organic halide (AOX)

PCTE for AOX

0.4 µm

• Low trace halides in membrane.

Densitometry

PCTE or PETE

• Uniform transmissivity of light within same lot.

Emission spectroscopy

PCTE or PETE

• Very low trace element background.

Gravimetric analysis

PCTE or PETE

• More accurate weight measurements.
• Matched weight filters not required.  Tare weight not significantly affected by sample adsorption.
• Low, constant tare and ash weights.
• Non-hygroscopic.  Tare weight not significantly changed by moisture adsorption.
• Reduced analysis time.

Microchemical analysis

PCTE or PETE

• Microchemical tests can be made on the membrane.
• Excellent chemical resistance.

Qualitative analysis

PCTE

• Surface capture of sample in one plane.
• Low trace elements in membrane.

Radioactive monitoring and analysis

PCTE or PETE

• Accurate, consistent measurements of low energy alpha and beta emissions from sample.
• Corrections for filter absorption eliminated.
• Best for fractionating radiocolloids.

X-ray diffraction

Silver

• Minimum of interfering spectra.
• NIOSH Method S315.

X-ray fluorescence

PCTE or PETE

• Membrane can be used for the target.
• Low trace elements-no characteristics radiation.
• Ideal for combined SEM/X-ray fluorescence analysis.

Plasmapheresis

PCTE or PETE

0.6, 0.8 µm

• Low h emolysis due to smooth membrane surface.
• Low non-specific binding of proteins.

Red blood cell deformability

PCTE for RBC deformability

4.7 µm

• Thinness and capillary pores of membrane allow near in-vivo measurements without hemolysis.

Red blood cell filtration

PCTE

8.0 µm

• Low hemolysis due to smooth membrane surface.

Studies of cells

Cell culture

PCTE or PETE

0.4 – 5.0 µm

• Near in-vivo conditions
• High diffusion rate.

Prefiltration of tissue culture media

Glass fiber filter

• High dirt loading capacity.
• Low cost.

Sterile filtration of tissue culture med

Autofil Laboratory Filtraton System

0.22 and 0.45 µm

• Excellent removal of microorganisms.
• Excellent throughput.

Chemotaxis

PCTE for chemotaxis

• Rapid cell migration.
• Reduced incubation times.
• Sterilization not necessary

Cytology

PCTE

3.0, 5.0, 8.0 µm

• All cells are in focus.
• Membrane does not stain.
• Resistant to alcohols, stains and xylene.
• No cell loss, cellular distortion, nor cell lysing.
• No RBCs, proteins, or cellular debris in specimen.
• High strength allows less critical handling.
• Simpler microscopic analysis.
• High flow rates minimize cell damage.

Prefiltration and coarse clarification

Glass fiber filter

• High dirt loading capacity.
• Low cost.

Beverage stabilization

MCE or Nylon

0.45 – 1.2 µm

• Absolute filtration.

Particulate and bacterial removal

PCTE, MCE, Nylon

0.1 – 5.0 µm

• Absolute removal.

Finish clarification

MCE or Nylon

0.22 – 1.0 µm

• High dirt loading capacity.
• Absolute filtration.

Fuel testing

MCE

0.45, 0.8 µm

• ASTM D2276

Liposome extrusion

PCTE

0.03 – 0.4 µm

• Consistency of vesicles.
• Faster than other methods.

Sterilizing filtrati

PCTE, MCE, Nylon

0.1 – 0.22 µm

• Absolute removal of bacteria.

Serum filtration

 MCE or Nylon

0.1 and 0.22 µm

• Absolute removal of microorganisms.
• Relatively high dirt loading capacity.

Gunshot residue test (GSR)

PETE

0.4 and 0.6 µm

• Surface capture in one plane.
• Excellent chemical resistance.

Microscopic examination of samples

PCTE or PETE

0.4 µm

• Surface capture in one plane of focus.

HPLC solutions filtration

Laminated PTFE, PVDF Discs and Syringe Filters

0.4 µm

• Excellent chemical resistance.
• High flow rates.

Concentration

PCTE or PETE

3.0 – 5.0 µm

• Low non-specific binding of microorganisms

Fractionation

PCTE or PETE

• Low non-specific binding of microorganisms

Cryptosporidium

PCTE

• Surface capture.

Giardia lamblia

PCTE

5.0 µm

• Low background clutter.

Harvesting

PCTE or PETE

• Surface capture of microorganisms.
• Ability to backwash for harvesting.

Observation

PCTE or PETE

0.2 – 0.8 µm

• Surface capture of microorganisms.
• Membrane is non-staining.

Direct Total

Microbial Count

PCTE

0.2 – 5.0 µm

• See Epifluorescent Microscopy under MICROSCOPY.

Dirofilaria immitis

PCTE

5.0 µm

• Surface capture of microfilaria.
• Membrane does not stain.

Legionella

PCTE

0.2 µm

• Low non-specific binding.

Shistosoma haematobium

PCTE

12.0 - 14.0 µm

• Surface capture.

Sterility testing

MCE

0.22 and 0.45 µm

• 21 CFR436

Total and fecal coliform

MCE

0.45 and 0.7 µm

• Standard Methods/Water and Waste water, 17^th Ed.

Yeasts and molds

PCTE (black)

0.6 and 0.8 µm

• Surface capture of sample.
• Membrane does not stain.

Direct optical observation

PCTE or PETE

0.2 and 0.4 µm

Electron microscopy

PCTE

0.1 – 5.0 µm

Epifluorescent microscopy

    Bacteria total count and observation.

    Yeast total count and observation.

    Spore observation

Black PCTE

0.2 – 5.0 µm

0.6 and 0.8 µm

5.0 µm

Single Wall Carbon Nanotube

Contruction/Analysis

PCTE

Template for nanomaterial development for Surface-Enhanced Raman Scattering (SERS)

PCTE

Alkaline elution

PCTE

0.8 – 2.0 µm

• Does not absorb DNA.
• DNA is retained intact.

Filtration of DNA fragments

PCTE

0.2 µm

• Single strand passes through filter without breaking.

Small volumes

MicroPrep syringe filters

• Convenient.

Prefiltration

Glass fiber filters

• Inexpensive and high dirt loading capacity.

Sterilization

MCE, Nylon

0.1 – 0.22 µm

• Absolute retention.
• 21 CFR 210 and 211.

Concentration / separation / fractionation / purification

PCTE or PETE

0.01 – 0.1 µm

• Low non-specific binding of viruses and proteins.

Observation

PCTE or PETE

0.01 and 0.03 µm

• Direct observation of viruses by epifluorescent microscopy.

Organic halides (AOX)

Low chlorine

PCTE

0.4 µm

• Undetectable halides from membrane in residual ash.

Nitrates, nitrites phosphates and ammonia

Low extractable

PCTE

0.45 µm

• Does not leach out chemicals of interest from membrane.

Culturing of microorganisms

MCE

0.22 – 0.7 µm

• Standard Methods/Water and Waste Water, 17^th Edition.

Direct count of microorganisms

Black PCTE

0.4 – 5.0 µm

• See Epifluorescent Microscopy under MICROSCOPY.