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Discos de membrana de ultrafiltración

Membranes for use with stirred cells

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    Amicon® Stirred Cell

    Referencias bibliográficas | 36 Disponible | Ver todas las referencias

    Visión general referenciasAplicación
    MicroRNA expression detected by oligonucleotide microarrays: System establishment and expression profiling in human tissues
    Omer Barad, Eti Meiri, Amir Avniel, Ranit Aharonov, Adi Barzilai, Isaac Bentwich, Uri Einav, Shlomit Gilad, Patrick Hurban, Yael Karov, Edward K. Lobenhofer, Eilon Sharon, Yoel M. Shiboleth, Marat Shtutman, Zvi Bentwich and Paz Einat
    Genome Research 14:2486-2494, 2004 2004

    Highly selective membranes in protein ultrafiltration
    Feins M, Sirkar KK,Biotechnol Bioeng. 2004 Jun 20;86(6):603-11
    Biotechnol Bioeng. 2004 Jun 20;86(6):603-11 2004

    Protein Purification
    Electrokinetic characterisation of ultrafiltration membranes by streaming potential, electroviscous effect, and salt retention
    Huisman IH (REPRINT) ; Pradanos P; Hernandez A
    Journal of membrane science 2000, V178, N1-2, p55-64 2000 2000

    Effect of Solution pH on Protein Transport Through Ultrafiltration Membranes
    Douglas B. Burns and Andrew L. Zydney
    Biotechnol Bioeng 64: 27-37, 1999. 1999

    Integrated process for the removal of emulsified oils from effluents in the steel industry
    Benito JM; Rios G; Gutierrez B; Pazos C; Coca J (REPRINT)
    Separation Science and Technology 1999, V34, N15, P3031-3043 SN- 0149-6395 1999

    Industrial QC
    Acrylamide production in an ultrafiltration-membrane bioreactor using cells of Brevibacterium imperialis CBS 489-74
    Cantarella M (reprint) ; Spera A; Cantarella L; Alfani F ; Journal of membrane science, v147, N2, p279-290 1998
    Journal of membrane science, v147, N2, p279-290 1998 1998

    Enzyme Assay
    In vitro and in vivo grafting of xeno pig fetal liver fragments using ultrafiltration membrane
    Kanai N.; Morita N.; Munkhbat B.; Gansuvd B.; Hagihara M.; Nagamachi Y.;Tsuji K.
    Cell Transplantation SO- 7/4 (417-420) 1998 1998

    Cell Culture
    Metabolic screening using on-line ultrafiltration mass spectrometry
    Van Breemen R.B.; Nikolic D.; Bolton J.L.
    Drug Metabolism and Disposition , 26/2 (85-90) 1998 1998

    Performance Characteristics of Waste Oil Emulsion Treatment by Ultrafiltration
    Lin, S. H.; Lan, W. J. Yuan Ze University, Taoyuan, Taiwan
    J Environ Sci Health-Toxic Hazard Subst Environ Eng 1998,SO- vA33, n3, p385(20) 1998

    General approach for the development of high-performance liquid chromatography methods for biosurfactant analysis and purification
    Lin, S.-C. Chen, Y.-C. Lin, Y.-M.
    J. Chromatogr., A ; Journal of Chromatography, A v. 825 pg 149-159 6 Nov 1998 1998

    Preguntas frecuentes

    How effective is ultrafiltration for fractionation of protein solutions? Ultrafiltration has limited utility for protein fractionation. Pore size distribution and membrane polarization effects contribute to the lack of separation precision. This is the reason for the wide spacing given to molecular weight cutoff points. Generally, an order of magnitude (10x) difference in molecule size is required to achieve reasonable separation. Separations may be enhanced by reducing the protein concentration, increasing agitation, or crossflow rate, or by optimizing buffers to minimize protein aggregation and adsorption.
    What molecular weight cut-off should I select for proteins of different sizes? As a rule, when using Ultracel membranes it is best to select a membrane 2-3 times smaller than the solute to be retained by the membrane. In the case of the Biomax membranes 4-5 times smaller than the NMWL is suggested. For more information on choosing the appropriate membrane cutt off: http://www.millipore.com/publications.nsf/docs/RF036
    What is the pH range for YM membrane? The pH range is 3-13.
    My recovery is low. Why? 1. What concentration are you using?
    a. If it is protein and <10ug/ml, the protein may be binding to the plastic (not the membrane). We suggest passivation (See passivation protocol).
    b. If it is DNA and >100ug/ml, most likely the DNA is precipitating out. There is no solution except use less DNA.

    2. Are you using a detergent?
    a. If yes, and it is greater than the critical micelle concentration, it will not pass through the membrane pores. Suggest diluting out the sample (See detergent study).
    What is the temperature limit for the Ultracel YM membrane? The temperature limit for the Ultracel YM membrane is 121 degrees C.
    What is the temperature limit for the Biomax membrane? The temperature limit for the Biomax membrane is 50 degrees C.
    What is the average thickness of the Ultracel YM membrane? The average thichness of the Ultracel YM membrane is 8 mil.
    What is the difference between Biomax and Ultracel membrane? Biomax is a polyethersulfone membrane designed with maximum flow characteristics. The protein retention is typically 80-85% of a globular solute with that molecular weight limit. Ultracel is a regenerated cellulose membrane designed with maximum recovery characteristics. The protein retention is typically 90-95% of a globular solute with that molecular weight limit.
    What are the different membranes types and advantages? MEMBRANE TYPE & MW Cut-off

    YMRegenerated Cellulose AcetateHigh Recovery
    PLRegenerated Cellulose AcetateHigh Recovery
    PM BioMaxPolyethersulfoneHigh Flux
    PM PolyethersulfoneHigh Flux
    PCRegenerated Cellulose AcetateHigh Recovery
    YCCellulose AcetateLowest MWCO
    What is the XM membrane? The XM ultrafiltration membrane consists of an acrylic copolymer (polyacrylonitrile/PVC). The polyacrylonitrile component is 43-49% by weight.
    What could be wrong if the stirrer assembly in the Stirred Cell won't spin? The stir bar won't spin unless the stirred cell is pressurized.
    What is the difference between Ultracel PL and Ultracel PLC membranes? Ultracel PL is Millipore's standard regenerated cellulose which is cast onto a non-woven Freudenberg substrate. Ultracel PLC is Millipore's composite regenerated cellulose that is cast onto a woven microporous polyethylene substrate. The Ultracel PLC is the leading edge void and defect free membrane construction that has superior resistance to reverse pressure.
    Are there any extractables in the UF disc membranes? The YM, PM and XM membranes are treated with glycerin as a humectant. The glycerin bath contains sodium azide as a preservative. The membranes contain no other extractables.
    Describe what happens when albumin (67,000 MW) and IgG (167,000 MW) are filtered through a 100,000 MW cut-off membrane? The larger solute will form a gel layer preventing the smaller solute from completely passing. If processed separately, the IgG would be retained and the albumin would pass through the membrane.
    How can I clean and restore the Ultracel and Biomax membranes after use? Rinse the membrane for 30 minutes with either 0.1 M NaOH, 100 ppm NaOCl (at 25 degrees C), or 0.1 - 0.5% chemical cleaner. After rinsing, flush the membrane thoroughly with distilled or deionized water.
    Is the Ultracel YM membrane autoclavable? Yes, the Ultracel YM membrane can be autoclaved, submerged in water, at 121 degrees C.
    Which UF membrane do I want, Biomax or Ultracel? Biomax is recommended for applications where very harsh pH conditions are required for processing or cleaning. Ultracel is recommended where harsh pH conditions are not needed and especially when protein loading is low (<20-g/m sq.) or the feedstock is highly fouling. Biomax is currently the premier UF membrane being used in Life Science applications, primarily due to its combination of low protein binding (i.e., high yield) and speed. Ultracel, Millipore’s new composite regenerated cellulose offering, is the lowest protein binding UF membrane available, making it ideal for dilute protein solutions where binding may be a significant factor in yield. For important applications, such as pilot trials prior to scale-up, it is recommended to conduct a trial with several pore sizes from each membrane family in order to determine which best meets the application criteria.
    What is the best way to store disc membranes? Solutions of 10% ethanol in water or 0.1% azide in water will preserve the membrane. For long-term storage, refrigeration is recommended.
    When doing diafiltration, how many initial volumes would it take to remove the salt? It takes three initial volumes to remove 95% of the salt and five initial volumes to remove 99.9% of the salt.
    As a rule of thumb, when separating two globular solutes, what size difference is required when performing ultrafiltration? In general, a 10 fold difference is recommended.

    Manuales del usuario

    Ultrafiltration Membranes - Operating Instructions