title: Single cell HaloChip assay on paper for point-of-care diagnosis.
abstract: This article describes a paper-based low cost single cell HaloChip assay that can be used to assess drug- and radiation-induced DNA damage at point-of-care. Printing ink on paper effectively blocks fluorescence of paper materials, provides high affinity to charged polyelectrolytes, and prevents penetration of water in paper. After exposure to drug or ionizing radiation, cells are patterned on paper to create discrete and ordered single cell arrays, embedded inside an agarose gel, lysed with alkaline solution to allow damaged DNA fragments to diffuse out of nucleus cores, and form diffusing halos in the gel matrix. After staining DNA with a fluorescent dye, characteristic halos formed around cells, and the level of DNA damage can be quantified by determining sizes of halos and nucleus with an image processing program based on MATLAB. With its low fabrication cost and easy operation, this HaloChip on paper platform will be attractive to rapidly and accurately determine DNA damage for point-of-care evaluation of drug efficacy and radiation condition. Graphical Abstract Single cell HaloChip on paper.
authors.affiliation: Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, Boston, MA, 02115, USA.|Wenzhou Institute of Biomaterials and Engineering, Wenzhou Medical University, Chinese Academy of Science, Wenzhou, Zhejiang, 325001, China.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, Boston, MA, 02115, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiao
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Ross
authors.initials: R
authors.lastname: Jones
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Narendra
authors.initials: N
authors.lastname: Singh
authors.affiliation: Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, Boston, MA, 02115, USA. m.su@neu.edu.|Wenzhou Institute of Biomaterials and Engineering, Wenzhou Medical University, Chinese Academy of Science, Wenzhou, Zhejiang, 325001, China. m.su@neu.edu.
authors.forename: Ming
authors.initials: M
authors.lastname: Su
mesh_terms: D052160:Benzothiazoles; D002460:Cell Line; D045744:Cell Line, Tumor; D020552:Comet Assay / Q000295:instrumentation*; D003603:Cytotoxins / Q000633:toxicity; D004247:DNA / Q000737:chemistry; D053938:DNA Fragmentation / Q000187:drug effects* / Q000528:radiation effects*; D003959:Diamines; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D005456:Fluorescent Dyes / Q000737:chemistry; D005720:Gamma Rays; D006801:Humans; D056656:Lab-On-A-Chip Devices; D061986:MCF-7 Cells; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D009930:Organic Chemicals / Q000737:chemistry; D010209:Paper; D019095:Point-of-Care Systems; D011804:Quinolines; D013194:Staining and Labeling / Q000379:methods
chemical_list: D052160:Benzothiazoles; D003603:Cytotoxins; D003959:Diamines; D005456:Fluorescent Dyes; D009930:Organic Chemicals; D011804:Quinolines; C098022:SYBR Green I; D004247:DNA
keywords: DNA damage; Paper-based assay; Point-of-care diagnosis; Single cell array