Polyvinylidene difluoride

FIG. 24-18 Sketch of housing and membrane cartridges for air filtration. Typical cartridges are 76 cm long and 7.36 cm in diameter of polyvinylidene difluoride with 0.22- im pores. 

P.V.D.F. Polyvinylidene difluoride is a coating which offers resistance to... 

The formulator must be aware of the potential for binding when filtering protein solutions. Because of the cost of most protein materials, a membrane should be used that minimizes protein adsorption to the membrane surface. Typical filter media that minimize this binding include hydrophilic polyvinylidene difluoride and hydroxyl-modified hydrophilic polyamide membranes [17a]. Filter suppliers will evaluate the compatibility of the drug product with their membrane media and also validate bacterial retention of the selected membrane. 

Figure 7.7. Protein microarray on polyvinylidene difluoride filters (PVDF). Proteins are gridded on filter and probed with an antibody to a gene of interest. Protein-ligand interactions could be detected using a labeled ligand as a probe.

The anodes of these two graphite samples were fabricated from a slurried mixture which contains 92 wt% of active graphite powder and 8wt% polyvinylidene difluoride (PVDF) polymer binder (Kureha 9130) and using 1 -methyl-2-pyrrolidinone (NMP) (Aldrich, >99%) as the solvent. After getting the homogenous slurry, the electrode laminates were coated on Cu current collector foil using a doctor blade in the laboratory-made laminate-coater. The laminates were then dried first at 75°C in air for 3 hrs and then the final heat treatment was carried out in a vacuum oven at 75 C for 10 hrs. Finally, the laminates were calendared to about 35% porosity in a dry room. 

The separated proteins were transferred to a polyvinylidene difluoride membrane, and nonspecific IgC binding sites were blocked by incubation with 5% nonfat dry milk for 1 h at room temperature. The membranes were then incubated overnight at 4°C with primary antibodies. Immune complexes were detected by enhanced chemiluminescence (Amersham Biosciences). 

Fig. 8. Tubular conduit made of woven polyvinylidene difluoride.

Fig. 10. Scanning electron microscopy microphotographies of the surface of different polystyrene-grafted polyvinylidene difluoride (PVDF) surfaces the grafting was performed upon irradiation with Argon ions with various fluences or absorbed doses, (a) PVDF-gAr-PS (V = 2.5%), D=3.72 kGy, (=1.1x10 ions/cm (b) PVDF-gAr-PS (V= 19%), D= 3.72 kGy,...

Use of Proteins Blotted to Polyvinylidene Difluoride Membranes as Immunogens... 

On completion of electrophoresis, proceed with transfer of glycoproteins onto a polyvinylidene difluoride (PVDF) membrane. Remember to discard the upper stacking gel and to wet the PVDF membrane in methanol before use. Wet transfer may be done according to the procedure described in Chapter 8 For semidry blotting, follow the procedure described in Chapter 20. 

In order to gain a direct experimental approach to probe the internal conversion of P, LIOAS was further developed to afford time-resolved measurements. For this purpose / -polyvinylidene difluoride foil was introduced [81] as a broad-frequency band piezoelectric detector—instead of the previously used ceramic transducers—which permitted for the first time the... 

Staining of blot transfer membranes permits visualization of proteins and allows the extent of transfer to be monitored. In the protocols described in this unit, proteins are stained after electroblotting from one-dimensional or two-dimensional polyacrylamide gels to blot membranes such as polyvinylidene difluoride (PVDF), nitrocellulose, or nylon membranes (unitb3.2). PVDF is the preferred, more universal membrane and is emphasized here however, most stains work similarly on nitrocellulose, and many can be used on alternative blotting membranes. 

PTFE polytetrafluoroethylene PUFA polyunsaturated fatty acid PV peroxide value PVDF polyvinylidene difluoride PVP polyvinylpyrrolidone PVPP polyvinylpolypyrolidone RAS retronasal aroma stimulator RDA recommended dietary allowance RF radio frequency RFI relative fluorescence intensity RI retention index RNU relative nitrogen utilization ROESY rotational nuclear Overhauser enhancement spectroscopy RP-HPLC reversed-phase HPLC RPER relative protein efficiency ratio RS resistant starch RT retention time RVP relative vapor pressure S sieman (unit of conductance)... 

Immunoblotting techniques involve the identification of a protein target via antigen-antibody-specific reactions. Proteins are typically separated by electrophoresis in polyacrylamide gels, and then transferred ( blotted ) onto chemically resilient membranes (e.g., nitrocellulose, polyvinylidene difluoride) where they bind in the pattern they took in the gel. The membrane is overlaid with a primary antibody directed to the specific target, then with a secondary antibody (anti-immunoglobulin) labeled with radioisotopes, enzymes or other marker compounds. 

Matsudaira, P. (1987) Sequence from picomole quantities of proteins electroblotted onto polyvinylidene difluoride membranes J. Biol. Chem. 262, 10,035-10,038. 

Wise, G. E. and Lin, F. (1991) Transfer of silver-stained proteins from polyacrylamide gels to polyvinylidene difluoride membranes. J. Biochem. Biophys. Methods 22, 223-231. 

Another approach to fraction collection is the use of an on-column frit structure or capillary fracture that depends on the electroosmotic flow to deposit the eluent in a continuous manner on a moving surface. Although this approach circumvents the dilution problem, the collection structures are complex and can result in the loss of some of the analyte. One commercially available fraction collection device couples CE with membrane fraction collection, without the need for frits or capillary fractures. The outlet vial holder can be removed and replaced with a wetted circular polyvinylidene difluoride (PVDF) disk, which enables the collection of eluted analytes and subsequent manipulations such as immunoblotting and microsequencing. Figure 6.13 shows a schematic diagram of the CE membrane fraction collector interface.74... 

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