Filtration Tutorial This tutorial is designed to enhance knowledge of the purification processes used in biotechnology. The topics covered in this tutorial are meant to provide a succinct overview of microfiltration and ultrafiltration processes. A more in-depth study will be referenced throughout the tutorial. It is recommended that an examination of the references be performed to further explain any of the concepts covered in this brief tutorial.

Overview  Types of Filtration  Microfiltration  How it works?  Ultrafiltration  How it works?  Microfiltration vs. Ultrafiltration  References

Types of Filtration  2 Examples: 1. Cross Flow 2. Dead End Flow Types of flow images from:

Type 1: Cross Filtration  Flow parallel to membrane surface  Does not cause buildup, therefore does not suffer from reduced flow overtime  F = feed; M = membrane; P = permeate; R = retentate (components that do NOT pass through the membrane) Cross Flow diagram from:

Type 2: Dead End Flow  Flow perpendicular to membrane surface  Causes build up of filter cake on membrane  F = feed; M = membrane; P = permeate (components that pass through membrane) Dead-end Flow diagram from:

Microfiltration  Separates soluble contaminants remaining within the supernatant  Supernatant may include:  Other proteins  Bio-molecules  Un-used growth media Microfiltration image from:

How does Microfiltration work?  Pressure driven process  Separates:  Components in a solution or suspension based on molecular size  Particles size range: 10  m (starches) to aprx  m (DNA, Viruses, and globular proteins) 10  m (starches) to aprx  m (DNA, Viruses, and globular proteins) Microfiltration image from: crofiltration/media/images/e-fluor.gif crofiltration/media/images/e-fluor.gif

Ultrafiltration  Usually used to further separate any contaminants able to pass through the microfiltration membrane using a pressure gradient Ultrafiltration image from:

How does Ultrafiltration work?  Separates:  Particle size range: 0.1  m to  m  Usually based on molecular weight  Typical range: 200 to 300,000 g/mole Ultrafiltration image from: ysis_works.htm ysis_works.htm

Microfiltration vs. Ultrafiltration  Microfiltration:  Proteins act as the permeate  Ultrafiltration  Proteins act as the retentate Images from: tration.com/html/ technology/ftech nology.html tration.com/html/ technology/ftech nology.html

Microfiltration vs. Ultrafiltration  Microfiltration:  Separates larger particles  For example-  Colloids  Fat globules  Cells  Located upstream to reduce load and fouling capacity on ultrafiltration membrane downstream  Ultrafiltration  Separates smaller particles  For example-  Macromolecules However, processes are basically identical

References [1] Case Study Solution - Facility Design for Antigenic Co-proteins (2003). CHE 451. NCSU [1] Case Study Solution - Facility Design for Antigenic Co-proteins (2003). CHE 451. NCSU [2] Grandison, A. S. & Lewis, M. J. (Eds.). (1996) Separation Processes in the Food and Biotechnology Industries. Woodhead Publishing. Retrieved November 30, 2003 from Knovel Chemistry and Chemical Engineering Database. [2] Grandison, A. S. & Lewis, M. J. (Eds.). (1996) Separation Processes in the Food and Biotechnology Industries. Woodhead Publishing. Retrieved November 30, 2003 from Knovel Chemistry and Chemical Engineering Database. [3] Zeman, L. J. & Zydney, A. L. (1996) Microfiltration and Ultrafiltration: Principles and Applications. New York: Marcel Dekker, Inc. Available via NCSU libraries as an eBook [3] Zeman, L. J. & Zydney, A. L. (1996) Microfiltration and Ultrafiltration: Principles and Applications. New York: Marcel Dekker, Inc. Available via NCSU libraries as an eBook