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Dive into the research topics where Erik S. Douglas is active.

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Featured researches published by Erik S. Douglas.


Proceedings of the National Academy of Sciences of the United States of America | 2008

Integrated microfluidic bioprocessor for single-cell gene expression analysis

Nicholas Toriello; Erik S. Douglas; Numrin Thaitrong; Sonny C. Hsiao; Matthew B. Francis; Carolyn R. Bertozzi; Richard A. Mathies

An integrated microdevice is developed for the analysis of gene expression in single cells. The system captures a single cell, transcribes and amplifies the mRNA, and quantitatively analyzes the products of interest. The key components of the microdevice include integrated nanoliter metering pumps, a 200-nL RT-PCR reactor with a single-cell capture pad, and an affinity capture matrix for the purification and concentration of products that is coupled to a microfabricated capillary electrophoresis separation channel for product analysis. Efficient microchip integration of these processes enables the sensitive and quantitative examination of gene expression variation at the single-cell level. This microdevice is used to measure siRNA knockdown of the GAPDH gene in individual Jurkat cells. Single-cell measurements suggests the presence of 2 distinct populations of cells with moderate (≈50%) or complete (≈0%) silencing. This stochastic variation in gene expression and silencing within single cells is masked by conventional bulk measurements.


Langmuir | 2009

Direct Cell Surface Modification with DNA for the Capture of Primary Cells and the Investigation of Myotube Formation on Defined Patterns

Sonny C. Hsiao; Betty J. Shum; Hiroaki Onoe; Erik S. Douglas; Zev J. Gartner; Richard A. Mathies; Carolyn R. Bertozzi; Matthew B. Francis

Previously, we reported a method for the attachment of living cells to surfaces through the hybridization of synthetic DNA strands attached to their plasma membrane. The oligonucleotides were introduced using metabolic carbohydrate engineering, which allowed reactive tailoring of the cell surface glycans for chemoselective bioconjugation. While this method is highly effective for cultured mammalian cells, we report here a significant improvement of this technique that allows the direct modification of cell surfaces with NHS-DNA conjugates. This method is rapid and efficient, allowing virtually any mammalian cell to be patterned on surfaces bearing complementary DNA in under 1 h. We demonstrate this technique using several types of cells that are generally incompatible with integrin-targeting approaches, including red blood cells and primary T-cells. Cardiac myoblasts were also captured. The immobilization procedure itself was found not to activate primary T-cells, in contrast to previously reported antibody- and lectin-based methods. Myoblast cells were patterned with high efficiency and remained undifferentiated after surface attachment. Upon changing to differentiation media, myotubes formed in the center of the patterned areas with an excellent degree of edge alignment. The availability of this new protocol greatly expands the applicability of the DNA-based attachment strategy for the generation of artificial tissues and the incorporation of living cells into device settings.


Lab on a Chip | 2009

DNA-barcode directed capture and electrochemical metabolic analysis of single mammalian cells on a microelectrode array

Erik S. Douglas; Sonny C. Hsiao; Hiroaki Onoe; Carolyn R. Bertozzi; Matthew B. Francis; Richard A. Mathies

A microdevice is developed for DNA-barcode directed capture of single cells on an array of pH-sensitive microelectrodes for metabolic analysis. Cells are modified with membrane-bound single-stranded DNA, and specific single-cell capture is directed by the complementary strand bound in the sensor area of the iridium oxide pH microelectrodes within a microfluidic channel. This bifunctional microelectrode array is demonstrated for the pH monitoring and differentiation of primary T cells and Jurkat T lymphoma cells. Single Jurkat cells exhibited an extracellular acidification rate of 11 milli-pH min(-1), while primary T cells exhibited only 2 milli-pH min(-1). This system can be used to capture non-adherent cells specifically and to discriminate between visually similar healthy and cancerous cells in a heterogeneous ensemble based on their altered metabolic properties.


Angewandte Chemie | 2006

Programmable cell adhesion encoded by DNA hybridization

Ravi A. Chandra; Erik S. Douglas; Richard A. Mathies; Carolyn R. Bertozzi; Matthew B. Francis


Archive | 2014

High numerical aperture telemicroscopy apparatus

Daniel A. Fletcher; Wendy Hansen; Neil Switz; David N. Breslauer; Erik S. Douglas; Robi N. Maamari; Jesse Dill


Analytical Chemistry | 2005

Microfluidic device for electric field-driven single-cell capture and activation.

Nicholas Toriello; Erik S. Douglas; Richard A. Mathies


Lab on a Chip | 2007

Self-assembled cellular microarrays patterned using DNA barcodes

Erik S. Douglas; Ravi A. Chandra; Carolyn R. Bertozzi; Richard A. Mathies; Matthew B. Francis


Archive | 2013

Cellscope apparatus and methods for imaging

Daniel A. Fletcher; Erik S. Douglas; Amy Sheng; Robi N. Maamari


Langmuir | 2012

Cellular microfabrication: observing intercellular interactions using lithographically-defined DNA capture sequences.

Hiroaki Onoe; Sonny C. Hsiao; Erik S. Douglas; Zev J. Gartner; Carolyn R. Bertozzi; Matthew B. Francis; Richard A. Mathies


Archive | 2016

DNA-cell conjugates

Shih-Chia Hsiao; Matthew B. Francis; Carolyn R. Bertozzi; Richard A. Mathies; Ravi A. Chandra; Erik S. Douglas; Amy Twite; Nicholas Toriello; Hiroaki Onoe

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Matthew B. Francis

Lawrence Berkeley National Laboratory

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Sonny C. Hsiao

University of California

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Amy Sheng

University of California

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