title: Magnetic levitation of single cells.
abstract: Several cellular events cause permanent or transient changes in inherent magnetic and density properties of cells. Characterizing these changes in cell populations is crucial to understand cellular heterogeneity in cancer, immune response, infectious diseases, drug resistance, and evolution. Although magnetic levitation has previously been used for macroscale objects, its use in life sciences has been hindered by the inability to levitate microscale objects and by the toxicity of metal salts previously applied for levitation. Here, we use magnetic levitation principles for biological characterization and monitoring of cells and cellular events. We demonstrate that each cell type (i.e., cancer, blood, bacteria, and yeast) has a characteristic levitation profile, which we distinguish at an unprecedented resolution of 1 × 10(-4) g ⋅ mL(-1). We have identified unique differences in levitation and density blueprints between breast, esophageal, colorectal, and nonsmall cell lung cancer cell lines, as well as heterogeneity within these seemingly homogenous cell populations. Furthermore, we demonstrate that changes in cellular density and levitation profiles can be monitored in real time at single-cell resolution, allowing quantification of heterogeneous temporal responses of each cell to environmental stressors. These data establish density as a powerful biomarker for investigating living systems and their responses. Thereby, our method enables rapid, density-based imaging and profiling of single cells with intriguing applications, such as label-free identification and monitoring of heterogeneous biological changes under various physiological conditions, including antibiotic or cancer treatment in personalized medicine.
authors.affiliation: Department of Biochemistry, School of Medicine, Stanford University, Stanford, CA 94304; Stanford Genome Technology Center, Stanford University, Stanford, CA 94304;
authors.forename: Naside Gozde
authors.initials: NG
authors.lastname: Durmus
authors.affiliation: Canary Center at Stanford for Cancer Early Detection, Radiology Department, School of Medicine, Stanford University, Stanford, CA 94304;
authors.forename: H Cumhur
authors.initials: HC
authors.lastname: Tekin
authors.affiliation: Canary Center at Stanford for Cancer Early Detection, Radiology Department, School of Medicine, Stanford University, Stanford, CA 94304;
authors.forename: Sinan
authors.initials: S
authors.lastname: Guven
authors.affiliation: Canary Center at Stanford for Cancer Early Detection, Radiology Department, School of Medicine, Stanford University, Stanford, CA 94304;
authors.forename: Kaushik
authors.initials: K
authors.lastname: Sridhar
authors.affiliation: Canary Center at Stanford for Cancer Early Detection, Radiology Department, School of Medicine, Stanford University, Stanford, CA 94304;
authors.forename: Ahu
authors.initials: A
authors.lastname: Arslan Yildiz
authors.affiliation: Canary Center at Stanford for Cancer Early Detection, Radiology Department, School of Medicine, Stanford University, Stanford, CA 94304;
authors.forename: Gizem
authors.initials: G
authors.lastname: Calibasi
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115; jeanne.thompson@stanford.edu larsms@stanford.edu utkan@stanford.edu.
authors.forename: Ionita
authors.initials: I
authors.lastname: Ghiran
authors.affiliation: Department of Biochemistry, School of Medicine, Stanford University, Stanford, CA 94304; Stanford Genome Technology Center, Stanford University, Stanford, CA 94304; Department of Genetics, School of Medicine, Stanford University, Stanford, CA 94304 jeanne.thompson@stanford.edu larsms@stanford.edu utkan@stanford.edu.
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Davis
authors.affiliation: Stanford Genome Technology Center, Stanford University, Stanford, CA 94304; Department of Genetics, School of Medicine, Stanford University, Stanford, CA 94304 jeanne.thompson@stanford.edu larsms@stanford.edu utkan@stanford.edu.
authors.forename: Lars M
authors.initials: LM
authors.lastname: Steinmetz
authors.affiliation: Canary Center at Stanford for Cancer Early Detection, Radiology Department, School of Medicine, Stanford University, Stanford, CA 94304; jeanne.thompson@stanford.edu larsms@stanford.edu utkan@stanford.edu.
authors.forename: Utkan
authors.initials: U
authors.lastname: Demirci
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D001419:Bacteria / Q000166:cytology / Q000187:drug effects; D045744:Cell Line, Tumor; D003470:Culture Media; D004912:Erythrocytes / Q000166:cytology; D006801:Humans; D007962:Leukocytes / Q000166:cytology; D008280:Magnetics; D008962:Models, Theoretical; D059010:Single-Cell Analysis; D015003:Yeasts / Q000166:cytology / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D003470:Culture Media
keywords: cancer; cell densitometry; magnetic levitation; real-time monitoring; single cells