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Norian H, Field RM, Kymissis I, Shepard KL. An integrated CMOS quantitative-polymerase-chain-reaction lab-on-chip for point-of-care diagnostics. LAB ON A CHIP 2014; 14:4076-84. [PMID: 25177916 DOI: 10.1039/c4lc00443d] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Considerable effort has recently been directed toward the miniaturization of quantitative-polymerase-chain-reaction (qPCR) instrumentation in an effort to reduce both cost and form factor for point-of-care applications. Considerable gains have been made in shrinking the required volumes of PCR reagents, but resultant prototypes retain their bench-top form factor either due to heavy heating plates or cumbersome optical sensing instrumentation. In this paper, we describe the use of complementary-metal-oxide semiconductor (CMOS) integrated circuit (IC) technology to produce a fully integrated qPCR lab-on-chip. Exploiting a 0.35 μm high-voltage CMOS process, the IC contains all of the key components for performing qPCR. Integrated resistive heaters and temperature sensors regulate the surface temperature of the chip to an accuracy of 0.45 °C. Electrowetting-on-dielectric microfluidics are actively driven from the chip surface, allowing for droplet generation and transport down to volumes less than 1.2 nanoliter. Integrated single-photon avalanche diodes (SPADs) are used for fluorescent monitoring of the reaction, allowing for the quantification of target DNA with more than four-orders-of-magnitude of dynamic range and sensitivities down to a single copy per droplet. Using this device, reliable and sensitive real-time proof-of-concept detection of Staphylococcus aureus (S. aureus) is demonstrated.
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Affiliation(s)
- Haig Norian
- Columbia University, Department of Electrical Engineering, 500 W. 120th St., New York, New York 10027, USA.
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Li B, Ding L, Yang C, Kang B, Liu L, Story MD, Pace BS. Characterization of transcription factor networks involved in umbilical cord blood CD34+ stem cells-derived erythropoiesis. PLoS One 2014; 9:e107133. [PMID: 25211130 PMCID: PMC4161396 DOI: 10.1371/journal.pone.0107133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Accepted: 08/11/2014] [Indexed: 11/19/2022] Open
Abstract
Fetal stem cells isolated from umbilical cord blood (UCB) possess a great capacity for proliferation and differentiation and serve as a valuable model system to study gene regulation. Expanded knowledge of the molecular control of hemoglobin synthesis will provide a basis for rational design of therapies for β-hemoglobinopathies. Transcriptome data are available for erythroid progenitors derived from adult stem cells, however studies to define molecular mechanisms controlling globin gene regulation during fetal erythropoiesis are limited. Here, we utilize UCB-CD34+ stem cells induced to undergo erythroid differentiation to characterize the transcriptome and transcription factor networks (TFNs) associated with the γ/β-globin switch during fetal erythropoiesis. UCB-CD34+ stem cells grown in the one-phase liquid culture system displayed a higher proliferative capacity than adult CD34+ stem cells. The γ/β-globin switch was observed after day 42 during fetal erythropoiesis in contrast to adult progenitors where the switch occurred around day 21. To gain insights into transcription factors involved in globin gene regulation, microarray analysis was performed on RNA isolated from UCB-CD34+ cell-derived erythroid progenitors harvested on day 21, 42, 49 and 56 using the HumanHT-12 Expression BeadChip. After data normalization, Gene Set Enrichment Analysis identified transcription factors (TFs) with significant changes in expression during the γ/β-globin switch. Forty-five TFs were silenced by day 56 (Profile-1) and 30 TFs were activated by day 56 (Profile-2). Both GSEA datasets were analyzed using the MIMI Cytoscape platform, which discovered TFNs centered on KLF4 and GATA2 (Profile-1) and KLF1 and GATA1 for Profile-2 genes. Subsequent shRNA studies in KU812 leukemia cells and human erythroid progenitors generated from UCB-CD34+ cells supported a negative role of MAFB in γ-globin regulation. The characteristics of erythroblasts derived from UCB-CD34+ stem cells including prolonged γ-globin expression combined with unique TFNs support novel mechanisms controlling the γ/β-globin switch during UCB-derived erythropoiesis.
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Affiliation(s)
- Biaoru Li
- Department of Pediatrics, Hematology/Oncology Division, Georgia Regents University, Augusta, Georgia, United States of America
| | - Lianghao Ding
- Department of Radiation Oncology and Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Chinrang Yang
- Department of Radiation Oncology and Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Baolin Kang
- Department of Pediatrics, Hematology/Oncology Division, Georgia Regents University, Augusta, Georgia, United States of America
| | - Li Liu
- Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, Texas, United States of America
| | - Michael D. Story
- Department of Radiation Oncology and Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Betty S. Pace
- Department of Pediatrics, Hematology/Oncology Division, Georgia Regents University, Augusta, Georgia, United States of America
- * E-mail:
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Khodakov DA, Ellis AV. Recent developments in nucleic acid identification using solid-phase enzymatic assays. Mikrochim Acta 2014. [DOI: 10.1007/s00604-014-1167-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Servoli E, Feitsma H, Kaptheijns B, van der Zaag PJ, Wimberger-Friedl R. Improving DNA capture on microarrays by integrated repeated denaturing. LAB ON A CHIP 2012; 12:4992-4999. [PMID: 23044700 DOI: 10.1039/c2lc40691h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Hybridization of nucleic acids to microarrays is a crucial step for several biological and biomedical applications. However, the poor efficiency and resulting long incubation times are major drawbacks. In addition to diffusion limitation, back hybridization to complementary strands in solution is shown to be an important cause of the low efficiency. In this paper, repeated denaturing in an integrated device has been investigated in order to increase the efficiency of microarray hybridization. The sample solution is circulated from the microarray chamber over a denaturing zone and back in a closed loop. In addition to the improved binding rate due to flow, repeated denaturing significantly increases the total amount of molecules bound. Our results demonstrate that cyclic repeated denaturing improves the efficiency of hybridization by up to an order of magnitude over a broad range of concentrations studied (1 pM to 100 nM).
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Affiliation(s)
- E Servoli
- Philips Research Laboratories, High Tech Campus 11, 5656 AE Eindhoven, The Netherlands
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Chandler DP, Bryant L, Griesemer SB, Gu R, Knickerbocker C, Kukhtin A, Parker J, Zimmerman C, George KS, Cooney CG. Integrated Amplification Microarrays for Infectious Disease Diagnostics. MICROARRAYS 2012; 1:107-24. [PMID: 27605339 PMCID: PMC5003434 DOI: 10.3390/microarrays1030107] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 10/31/2012] [Accepted: 11/07/2012] [Indexed: 11/17/2022]
Abstract
This overview describes microarray-based tests that combine solution-phase amplification chemistry and microarray hybridization within a single microfluidic chamber. The integrated biochemical approach improves microarray workflow for diagnostic applications by reducing the number of steps and minimizing the potential for sample or amplicon cross-contamination. Examples described herein illustrate a basic, integrated approach for DNA and RNA genomes, and a simple consumable architecture for incorporating wash steps while retaining an entirely closed system. It is anticipated that integrated microarray biochemistry will provide an opportunity to significantly reduce the complexity and cost of microarray consumables, equipment, and workflow, which in turn will enable a broader spectrum of users to exploit the intrinsic multiplexing power of microarrays for infectious disease diagnostics.
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Affiliation(s)
- Darrell P Chandler
- Akonni Biosystems, Inc., 400 Sagner Avenue, Suite 300, Frederick, MD 21701, USA.
| | - Lexi Bryant
- Akonni Biosystems, Inc., 400 Sagner Avenue, Suite 300, Frederick, MD 21701, USA.
| | - Sara B Griesemer
- Laboratory of Viral Diseases, Wadsworth Center, New York State Dept of Health, 120 New Scotland Avenue, Albany, NY 12208, USA.
| | - Rui Gu
- Laboratory of Viral Diseases, Wadsworth Center, New York State Dept of Health, 120 New Scotland Avenue, Albany, NY 12208, USA.
| | | | - Alexander Kukhtin
- Akonni Biosystems, Inc., 400 Sagner Avenue, Suite 300, Frederick, MD 21701, USA.
| | - Jennifer Parker
- Akonni Biosystems, Inc., 400 Sagner Avenue, Suite 300, Frederick, MD 21701, USA.
| | - Cynthia Zimmerman
- Akonni Biosystems, Inc., 400 Sagner Avenue, Suite 300, Frederick, MD 21701, USA.
| | - Kirsten St George
- Laboratory of Viral Diseases, Wadsworth Center, New York State Dept of Health, 120 New Scotland Avenue, Albany, NY 12208, USA.
| | - Christopher G Cooney
- Akonni Biosystems, Inc., 400 Sagner Avenue, Suite 300, Frederick, MD 21701, USA.
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