Office of Technology Transfer – University of Michigan

Biological Separations with Magnetic Beads and Pathogen Removal

Technology #5577

This technology enables targeted separation, and hence removal, of bacteria from liquids by using specially developed magnetic beads to label selectively bacteria or pathogens. Consequently, this technology can be used to clean blood products or pharmaceutical preparations from harmful bacteria.

Affinity magnetic beads are commonly used to detect or concentrate biologics of interest. The principle works by using magnetic beads that are decorated with ligand, which bind to the analyte of interest. These magnetic beads, with their bound analytes, can be separated from the remainder of the solution with magnetic fields or centrifugation. Consequently, this technique could potentially be used to remove unwanted pathogens and biologics from blood products, food products, or pharmaceutical preparations. Current methods often focus on pathogen inactivation, whereas, this technology would involve physically removing the offending pathogens for later identification. Ideally, the removal processes of pathogens would be fairly non-specific for all pathogens, employ FDA approved features, and avoid harm to the original product.

Bacteria-Targeted Magnetic Beads

Researchers in the Department of Chemistry have developed a new material coating for magnetic beads used to separate biologics. This material coating enables the beads to bind selectively all gram-positive bacteria in a sample with high affinity, and thus, enables removal of the bead-bound bacteria from the sample. During the removal processes, the gram-positive bacteria can be concentrated and easily identified using fluorescence-based methods. This technology will have applications in pathogen removal and detection in blood, food, and pharmaceutical products. In particular, this technology may be very useful for pathogen removal from platelet products, since these samples must be maintained at room temperature and are thus susceptible to bacterial growth.


  • Separation of gram-positive bacteria from fluids
  • Pathogen removal from blood, food, and pharmaceutical products


  • Avoids chemical treatment of the sample
  • Concentrates bacteria for identification