A multi-dimensional approach for fractionating proteins using charged membranes

Authors

  • Mirco Sorci,

    1. Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180; telephone: +518-276-6948; fax: +518-276-4030
    Search for more papers by this author
  • Minghao Gu,

    1. Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180; telephone: +518-276-6948; fax: +518-276-4030
    Search for more papers by this author
  • Caryn L. Heldt,

    1. Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180; telephone: +518-276-6948; fax: +518-276-4030
    Current affiliation:
    1. Department of Chemical Engineering, Michigan Tech, Houghton, MI 49931
    Search for more papers by this author
  • Elizabeth Grafeld,

    1. Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180; telephone: +518-276-6948; fax: +518-276-4030
    Search for more papers by this author
  • Georges Belfort

    Corresponding author
    1. Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180; telephone: +518-276-6948; fax: +518-276-4030
    • Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180; telephone: +518-276-6948; fax: +518-276-4030.
    Search for more papers by this author

Abstract

In an effort to increase selectivity among proteins with crossflow ultrafiltration, we offer and demonstrate a comprehensive approach to fractionate proteins of similar molecular weight and relatively close pI values. This multidimensional approach involves optimizing membrane charge type and density together with operating conditions such as precise control of pH, ionic strength, and transmembrane pressure for reduced membrane fouling. Each filtration experiment was performed in cross-flow configuration for ∼20 min, allowing fast screening for optimal separation as determined by maximum selectivity, Ψ, and purity, P. Using our comprehensive approach for fractionating mixtures RNase A–lysozyme and BSA–hemoglobin, we obtained values of Ψ = 9.1, P = 95.7%, and Ψ = 6.5, P = 62.1%, respectively. Biotechnol. Bioeng. 2013; 110: 1704–1713. © 2013 Wiley Periodicals, Inc.

Ancillary