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F A Q S
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VISKING . COM |
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QUESTIONS ABOUT BUYING THE MEMBRANES
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We are happy to answer any questions about the product but to help you get answers to the most common questions we have set up this page. We hope that you will find it helpful.
WHY DO I NEED TO CLEAN THE MEMBRANES? The membranes are supplied in a dry form and have glycerol present to act as a humectant. This must always be removed for the membranes to work. In addition there are some impurities present which may have a bearing on your results (see the composition page). The cleaning procedures are outlined on the preparation page.
HOW LONG DO THE MEMBRANES KEEP? The dry membrane should be stored away from direct sunlight in a minimum relative humidity of 35% at a temperature of 23ºC. Membranes keep well under these conditions but should always be examined to ensure no drying out has occurred. Prepared membranes should always be stored wet with some sort of preservative solution. Prepared membranes should not be kept for longer than a few days. For more details see the preparation page.
VISKING MEMBRANES DO NOT QUITE SUIT MY NEEDS, ARE THERE ALTERNATIVES THAT YOU CAN RECOMMEND? Although the membranes are generally a suitable tool for most circumstances the end user may occasionally require membranes with a different cut-off or slightly different composition. Contact MEDICELL INTERNATIONAL LTD for details of alternative membranes available.
QUESTIONS ABOUT BUYING THE MEMBRANES
HOW CAN I BUY VISKING MEMBRANES? The VISKING range of membranes is available worldwide through MEDICELL INTERNATIONAL and their agents. Contact them directly for details.
DO YOU TAKE CREDIT CARDS? Medicell International are pleased to accept credit cards under most circumstances.
HOW MUCH DO THE VISKING MEMBRANES COST? The cost of the membranes varies according to local circumstances and agreements. Please contact us for a price list for your region.
DO YOU HAVE AN AGENT IN MY COUNTRY? MEDICELL INTERNATIONAL has agents in a number of countries and where such agency agreements have not been set up it is possible for buyers to order directly from them. Please contact us or Medicell for details.
GENERAL QUESTIONS ABOUT FILTRATION
WHAT DOES MOLECULAR WEIGHT CUTOFF (MWCO) MEAN? Dialysis membranes are graded according to Molecular Weight Cut Off, that is where 90% of the solute will be retained by the membrane. In addition to molecular weight, the exact permeability of a solute is dependent on the shape of the molecule, its degree of hydration and its charge. Each of these may be influenced by the nature of the solvent, its pH and ionic strength, consequently MWCO should be used as a guide and not an absolute indicator of performance.
WHICH MEMBRANE MOST SUITS MY NEEDS?
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LAST UPDATED 13 Sep 2004 |
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