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Centrifree® Ultrafiltration Device

Separate free from unbound solutes

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Centrifree Ultrafiltration Device Clear Sorting & Filtering
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4104Centrifree Ultrafiltration Device with Ultracel PL membrane 50 Show Pricing & Availability

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    Technical Info

    Assay of Free Anticonvulsant Drugs
    Clinical Guidelines for Monitoring Free Drug Concentration: An Overview

    References | 95 Available | See All References

    Reference overviewApplication
    Fractionation of canine serum magnesium.
    Schenck PA.,Vet Clin Pathol. 2005 Jun;34(2):137-9.
    Vet Clin Pathol. 2005 Jun;34(2):137-9. 2005

    The indirect effect of Tityus discrepans on rabbit pulmonary vasculature.
    Novoa, Eva, et al.
    Respiratory physiology & neurobiology, 134: 33-41 (2003) 2003

    Show Abstract
    Cell Culture
    Metabolic activity of cultured rat brainstem, hippocampal and spinal cord slices.
    Caroline A. Connelly, Lawrence C. Chen and Steven D. Colquhoun
    Journal of Neuroscience Methods 99 (1-2): 1-7 2000

    Cell Culture
    Adaptation of total phenytoin reagent pack for measuring free phenytoin levels with the Abbott AxSYM immunoassay analyzer
    Jarzabek JI (REPRINT) ; Kampa IS
    Therapeutic drug monitoring 1999, v21, n1, p134-136 1999

    Phenylalanine and tyrosine quantification by stable isotope dilution liquid chromatography-mass spectrometry from filter paper blood spots
    Tuchman, M. McCann, M. T.
    Clinical Chemistry (Washington, D. C.) VO- 45 IS- 4 PG- 571-573 Apr 1999 1999

    Sample Prep
    Circadian rhythm of free melatonin in human plasma
    Kennaway DJ (REPRINT) ; Voultsios A

    Clinical Lab, Protein Binding
    Factors affecting the free plasma fraction of phenytoin in patients with epilepsy
    Jimenez MC; Duran JA (REPRINT) ; Abadin JA
    Clinical drug investigation, 1998, V15, P153-157 1998

    Clinical Lab
    Differential analysis of blood urea using combined automated ultrafiltration and solid phase extraction in on-line series
    Shintani H.,Journal of Liquid Chromatography and Related Technologies (2205-2210) 1998
    Journal of Liquid Chromatography and Related Technologies (2205-2210) 1998 1998

    Effects of tryptophan depletion vs. catecholamine depletion in patients with seasonal affective disorder in remission with light therapy
    Neumeister, Alexander et al.
    Archives of general psychiatry, 1998 1998

    Valproic acid-ketoconazole interaction in normal, hypoalbuminemic, and uremic sera: Lack of interaction in uremic serum caused by the presence of inhibitor
    Dasgupta Amitava(a); Luke Matthew; Therapeutic Drug Monitoring VO- 19 IS- 3 PG- 281-285 June, 1997 SN- 0163-4356
    Therapeutic Drug Monitoring VO- 19 IS- 3 PG- 281-285 June, 1997 SN- 0163-4356 1997


    Can I use Centrifree with a swinging-bucket rotor? Yes, but the filtration rate will be only 30-50% of that produced with a fixed-angle rotor at the same g-force.
    What are the pore and retention characteristics of the YMT 30,000 molecular weight cut-off membrane for Centrifree micropartition device? The actual pore size is not measured. The membrane is characterized by measuring its retention of known protein markers of specific molecular weights. The given cut-off is a nominal measurement.
    What is the maximum spinning speed of the Centrifree unit? Device limits are measured in g-force, not rpm. The maximum recommended g-force is 2000 × g.
    How much ultrafiltrate can I expect when using the Centrifree? For volumes less than 0.5 ml: For a sample volume of 1.0 ml: In 10 minutes: I 1/2 the initial volume approximately 200 µl In 30 minutes: 2/3 to 3/4 the initial volume approximately 450 µl
    What is the maximum process volume for the Centrifree device? Maximum volume is 1.0 ml.
    What molecular weight cut-off does the Centrifree come in? The Centrifree unit is available in a 30,000 MW cut-off.
    Can I reuse Centrifree? No, Centrifree is intended for one-time use only. Multiple use risks membrane failure.
    What is the minimum process volume for the Centrifree device? Minimum volume is 0.15 ml.
    What temperatures can Centrifree be spun at? Spin devices at 4-50°C. Store at room temperature.
    What centrifuge can I use with the Centrifree? Any centrifuge with a fixed angle rotor or carrier that can accommodate 17 × 100 mm tubes and is capable of 1000-2000 g.
    Can I sterilize Centrifree? Yes. Centrifree can be sterilized using ethylene oxide gas.
    How long do I spin the Centrifree? 1ml of normal human serum spun in a fixed angle rotor will produce 125-130ul of ultrafiltrate in 10 minutes. 1ml of normal human serum spun in a swinging bucket will produce 115-120ul of ultrafiltrate in 10 minutes.
    Is Centrifree autoclavable? No, the Centrifree unit is not autoclavable.
    When using the Centrifree unit, why do identical serum samples occasionally have different flow rates in my swinging-bucket rotor? When using a swinging-bucket rotor, the pattern of buildup of retained protein at the membrane surface is random, therefore it is not unusual to detect different flow rates. Because that protein layer is able to cover the entire membrane surface, the flow rate is slower compared to the rate in a fixed-angle rotor. Use of a fixed-angle rotor counteracts buildup of retained protein at the membrane surface because the angle causes this dense protein layer to slide outward and accumulate at the edge of the membrane.
    When was the color/material of the Centrifree O-ring changed? The color was changed from gray bromobutyl to black ethylene-propylene-diene-monomer(EPDM) in 1999. The product’s specifications and functional performance will not be altered as a result of this change in material.
    Does Centrifree have a shelf life? Yes, one year.
    What membranes should I use with MPS-1? The MPS-1 unit accepts a variety of 14mm membranes. The following is a list of molecular weight cut-offs available and the corresponding catalog numbers: