Edition: U.S.

Spectrum Labs, the leader in filtration and laboratory dialysis.
site map | search> 
 
Click to register to shop on-lineClick for information on how to contact us.Click for information about who we are.Click for print formatted product literature.Click to fill out our customer satisfaction survey.Click for information on which trade shows we will be attending.
New Products
Filtration Products
Disposable Bag Products
Perfusion Assemblies and Systems at Spectrum Labs
Laboratory Dialysis Products
Membrane Dialysis
Dynamic Dialysis
Labware Products
Cell Culture Products
Chromatography Products
Operating Room Disposables
OEM Products

We are ISO 9001:2008 certified
Newsletter Sign-up

Fundamentals of Membrane Dialysis

Dialysis is a simple process in which small solutes diffuse from a high concentration solution to a low concentration solution across a semipermeable membrane until equilibrium is reached. Since the porous membrane selectively allows smaller solutes to pass while retaining larger species, dialysis can effectively be used as a separation process based on size rejection. The conditions of dialysis can be controlled or manipulated to produce desired results for a variety of dialysis applications. The application depicts which Molecular Weight Cut Off (MWCO) yields the preferred molecular separation.

ADVANTAGES OF LAB DIALYSIS

  • Very Gentle Conditions
  • Easy Operation
  • Wide Range of Sample Volumes
  • Many Membrane Types & MWCO's
  • Inexpensive Materials
  • Disposable Membranes & Devices

Dialysis Applications

  • Macromolecular Purification
  • Protein Concentration
  • Solute Fractionation
  • Contaminant Removal
  • pH Change
  • Desalting
  • Buffer Exchange
  • Binding Studies
  • Electro-elution

Selecting the Right Molecular Weight Cut Off (MWCO)


Since the dialysis membrane consists of a spongy matrix of crosslinked polymers, the pore rating referred to as Molecular Weight Cut Off (MWCO), is an indirect measure of the retention performance. More precisely, the membrane MWCO is determined as the solute size that is retained by at least 90%. However, since a solute's permeability is also dependent upon molecular shape, degree of hydration, ionic charge and polarity, it is recommended to select a MWCO that is half the size of the MW of the species to be retained and at least 10 times larger than twice the size of the MW of the species intended to pass through.

Use a credit card on-line and get a 20% discount! Details here.
Membrane Selection Guide
Frequently Asked Questions (FAQs)
Chemical Compatibility
Pore Size Chart
Application Notes

Have a dialysis question? Try labdialysischat.com

hi dave
copyright © 1995-2014 SPECTRUM® LABORATORIES, INC All rights reserved | Privacy Policy | Sales Terms and Conditions | Site FAQ's
 
You can order on-line using a credit card or purchase order or call us to use almost any form of payment.Click to register to shop.Click to register to shop.Click to register to shop.Click for a list of our phone numbers.