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dc.contributor.advisorWhitesides, George McClelland
dc.contributor.advisorWestervelt, Robert M.
dc.contributor.authorKumar, Ashok Ashwin
dc.date.accessioned2014-06-06T20:02:55Z
dash.embargo.terms2015-06-04en_US
dash.embargo.terms2015-06-04
dc.date.issued2014-06-06
dc.date.submitted2014
dc.identifier.citationKumar, Ashok Ashwin. 2014. Density-Based Separations in Aqueous Multiphase Systems: Tools for Biological Research and Low-Cost Diagnostics. Doctoral dissertation, Harvard University.en_US
dc.identifier.otherhttp://dissertations.umi.com/gsas.harvard:11491en
dc.identifier.urihttp://nrs.harvard.edu/urn-3:HUL.InstRepos:12274502
dc.description.abstractCells often exist in heterogeneous mixtures. Density provides a property to separate several types of cells from the mixed sample in which they originate. Density-based separation methods provide a standard method to quickly separate or enrich specific populations of cells, such as lymphocytes from whole blood. This dissertation explores the use of aqueous multiphase systems (AMPS) as self-forming step-gradients in density for the separation of cells. AMPS were first discovered over a hundred years ago as aqueous two-phase systems. Density as a tool to separate cells is at least as old. Despite this long history, the work in this thesis is the first work to use AMPS to perform density-based separations on cells. This combination provides a powerful technique to separate cells and enable new testing at the point-of-care. Chapter 1 provides a short overview of aqueous multiphase systems and density-based separations of cells. Chapter 2 describes the process of taking technology, including AMPS, from a demonstration in a laboratory to a large scale evaluation in a field setting. In Chapter 3 and Appendix I, AMPS provide a means to enrich reticulocytes from whole blood as a means to grow malaria parasites. Chapter 4 and Appendix II describe the development and proof-of-prinicple of a density-based diagnostic test for sickle cell disease (SCD) using AMPS. Chapter 5 and Appendix III detail the results of a large scale field evaluation of a rapid test for SCD using AMPS in Zambia. Demonstrations of AMPS for density- and size-based separations are provided in Appendices IV and V. Appendix VI demonstrates the general usefulness of density to separate crystal polymorphs with another density-based separation method: magnetic levitation in a paramagnetic fluid. Beyond density, novel combinations of technology, such as electrochemistry and telecommunications provide opportunities for enabling global health (Appendix VII).en_US
dc.description.sponsorshipEngineering and Applied Sciencesen_US
dc.language.isoen_USen_US
dash.licenseLAA
dc.subjectBiomedical engineeringen_US
dc.subjectBiophysicsen_US
dc.subjectdensity gradienten_US
dc.subjectdiagnosticsen_US
dc.subjectpoint-of-careen_US
dc.subjectpolymersen_US
dc.subjectreticulocytesen_US
dc.subjectsickle cell diseaseen_US
dc.titleDensity-Based Separations in Aqueous Multiphase Systems: Tools for Biological Research and Low-Cost Diagnosticsen_US
dc.typeThesis or Dissertationen_US
dash.depositing.authorKumar, Ashok Ashwin
dc.date.available2015-06-04T07:30:48Z
thesis.degree.date2014en_US
thesis.degree.disciplineEngineering and Applied Sciencesen_US
thesis.degree.grantorHarvard Universityen_US
thesis.degree.leveldoctoralen_US
thesis.degree.namePh.D.en_US
dc.contributor.committeeMemberAizenberg, Joannaen_US
dc.contributor.committeeMemberWirth, Dyannen_US
dash.contributor.affiliatedKumar, Ashok Ashwin


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