title: Kinetically limited differential centrifugation as an inexpensive and readily available alternative to centrifugal elutriation.
abstract: When separating two species with similar densities but differing sedimentation velocities (because of differences in size), centrifugal elutriation is generally the method of choice. However, a major drawback to this approach is the requirement for specialized equipment. Here, we present a new method that achieves similar separations using standard benchtop centrifuges by loading the seperands as a layer on top of a dense buffer of a specified length, and running the benchtop centrifugation process for a calculated amount of time, thereby ensuring that all faster moving species are collected at the bottom, while all slower moving species remain in the buffer. We demonstrate the use of our procedure to isolate bacteria from blood culture broth (a mixture of bacterial growth media, blood, and bacteria).
authors.affiliation: Department of Biological Engineering, University of Missouri, Columbia, MO, USA.
authors.forename: Jinwang
authors.initials: J
authors.lastname: Tan
authors.forename: Byung-Doo
authors.initials: BD
authors.lastname: Lee
authors.forename: Luis
authors.initials: L
authors.lastname: Polo-Parada
authors.forename: Shramik
authors.initials: S
authors.lastname: Sengupta
mesh_terms: D000465:Algorithms; D001419:Bacteria / Q000302:isolation & purification*; D001773:Blood Cells / Q000166:cytology*; D002021:Buffers; D002469:Cell Separation / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D002498:Centrifugation / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D004912:Erythrocytes / Q000166:cytology; D006801:Humans; D007700:Kinetics
chemical_list: D002021:Buffers