title: Cell loss in integrated microfluidic device.
abstract: Cell loss during sample transporting from macro-components to micro-components in integrated microfluidic devices can considerably deteriorate cell detection sensitivity. This intrinsic cell loss was studied and effectively minimized through (a) increasing the tubing diameter connecting the sample storage and the micro-device, (b) applying a hydrodynamic focusing approach for sample delivering to reduce cells contacting and adhesion on the walls of micro-channel and chip inlet; (c) optimizing the filter design with a zigzag arrangement of pillars (13 microm in chamber depth and 0.8 microm in gap) to prolong the effective filter length, and iv) the use of diamond shaped pillar instead of normally used rectangular shape to reduce the gap length between any two given pillar (i.e. pressure drop) at the filter region. Cell trapping and immunofluorescent detection of 12 Giardia lamblia and 12 Cryptosporidium parvum cells in 150 microl solution and 50 MCF-7 breast cancer cells in 150 microl solution was completed within 15 min with trapping efficiencies improved from 79+/-11%, 50.8+/-5.5% and 41.3+/-3.6% without hydrodynamic focusing, respectively, to 90.8+/-5.8%, 89.8+/-16.6% and 77.0+/-9.2% with hydrodynamic focusing.
authors.affiliation: Institute of Microelectronics, Agency for Science, Technology and Research, 11 Science Park Road, Singapore Science Park II, Singapore, Singapore, 117685.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhu
authors.forename: Xue Li
authors.initials: XL
authors.lastname: Peh
authors.forename: Hong Miao
authors.initials: HM
authors.lastname: Ji
authors.forename: Cheng Yong
authors.initials: CY
authors.lastname: Teo
authors.forename: Han Hua
authors.initials: HH
authors.lastname: Feng
authors.forename: Wen-Tso
authors.initials: WT
authors.lastname: Liu
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D001943:Breast Neoplasms / Q000473:pathology; D045744:Cell Line, Tumor; D016785:Cryptosporidium parvum / Q000166:cytology / Q000276:immunology / Q000302:isolation & purification*; D005260:Female; D005374:Filtration / Q000379:methods; D019084:Fluorescent Antibody Technique, Indirect; D016829:Giardia lamblia / Q000166:cytology / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D011142:Polyvinyl Alcohol / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D012822:Silicon Dioxide; D011142:Polyvinyl Alcohol