1 Supporting information Homogeneous differential magnetic assay Sobhan Sepehri †* , Teresa Zardán Gómez de la Torre ‡ , Justin F. Schneiderman †§ , Jakob Blomgren ∥ , Aldo Jesorka ¶ , Christer Johansson ∥ , Mats Nilsson ⊥ , Jan Albert □ ∎ , Maria Strømme ‡ , Dag Winkler † , and Alexei Kalaboukhov † † Department of Microtechnology and Nanoscience – MC2, Chalmers University of Technology, SE-412 96 Göteborg, Sweden. ‡ Department of Engineering Sciences, Uppsala University, The Ångström Laboratory, Box 534, SE-751 21 Uppsala, Sweden. § MedTech West and the Institute of Neuroscience and Physiology, University of Gothenburg, SE-40530 Göteborg, Sweden. ∥ RISE – Research Institute of Sweden, SE-411 33 Göteborg, Sweden. ¶ Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden. ⊥ Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Box 1031,SE-171 21 Solna, Sweden. □ Department of Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden. ∎ Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, SE- 171 76 Stockholm, Sweden.