Membrane for Selective Capture of the Microbial Pathogen Listeria monocytogenes

Membrane filtration is widely used for sterile filtration, flowthrough immuno-filtration, virus removal, and microbiological analysis.1,2,3,4,5,6 Prior work has described membranes that retain one protein over others.7,8 The purpose of this work is to capture a target species of living cells from a mixed population of microorganisms being concentrated in the retentate of solution being pushed through a membrane. We report selective capture of one living microorganism from another by an antibody immobilized on a lysine-modified polycarbonate membrane. Capture of a relatively large microbial entity (L. monocytogenes at 1 m) by a 75 to 150 fold smaller ligand (the antibody) occurs with high efficiency, when a spacer (poly-Llysine) reacted to the membrane’s surface is derivatized with an antibody (P66) specific to Listeria. The results show that isolation of the food pathogen L. monocytogenes from E. coli in less than 2 h is possible.