Alex Groisman

Summary

Affiliation: University of California
Country: USA

Publications

  1. ncbi request reprint A microfluidic chemostat for experiments with bacterial and yeast cells
    Alex Groisman
    Department of Physics, University of California San Diego, 9500 Gilman Dr, MC 0374, La Jolla, California 92093, USA
    Nat Methods 2:685-9. 2005
  2. ncbi request reprint MAPK-mediated bimodal gene expression and adaptive gradient sensing in yeast
    Saurabh Paliwal
    Department of Biomedical Engineering and Whitaker Institute of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
    Nature 446:46-51. 2007
  3. pmc Self-organization in high-density bacterial colonies: efficient crowd control
    HoJung Cho
    Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, Maryland, United States of America
    PLoS Biol 5:e302. 2007
  4. ncbi request reprint Optofluidic 1x4 switch
    Alex Groisman
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 0374, USA
    Opt Express 16:13499-508. 2008
  5. ncbi request reprint Generation of complex concentration profiles in microchannels in a logarithmically small number of steps
    Kyle Campbell
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
    Lab Chip 7:264-72. 2007
  6. pmc Innate non-specific cell substratum adhesion
    William F Loomis
    Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
    PLoS ONE 7:e42033. 2012
  7. doi request reprint Incoherent feedforward control governs adaptation of activated ras in a eukaryotic chemotaxis pathway
    Kosuke Takeda
    Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
    Sci Signal 5:ra2. 2012
  8. pmc Gradient sensing in defined chemotactic fields
    Monica Skoge
    Division of Biological Sciences, University of California, La Jolla, CA 92093, USA
    Integr Biol (Camb) 2:659-68. 2010
  9. pmc High refractive index silicone gels for simultaneous total internal reflection fluorescence and traction force microscopy of adherent cells
    Edgar Gutierrez
    Department of Physics, University of California San Diego, La Jolla, California, United States of America
    PLoS ONE 6:e23807. 2011
  10. pmc Visualizing a one-way protein encounter complex by ultrafast single-molecule mixing
    Yann Gambin
    Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
    Nat Methods 8:239-41. 2011

Collaborators

Detail Information

Publications35

  1. ncbi request reprint A microfluidic chemostat for experiments with bacterial and yeast cells
    Alex Groisman
    Department of Physics, University of California San Diego, 9500 Gilman Dr, MC 0374, La Jolla, California 92093, USA
    Nat Methods 2:685-9. 2005
    ....
  2. ncbi request reprint MAPK-mediated bimodal gene expression and adaptive gradient sensing in yeast
    Saurabh Paliwal
    Department of Biomedical Engineering and Whitaker Institute of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
    Nature 446:46-51. 2007
    ..In addition, the dynamic range of gradient sensing of Kss1-deficient cells was reduced compared with wild type. We thus provide unsuspected functional significance for this kinase in regulation of the mating response...
  3. pmc Self-organization in high-density bacterial colonies: efficient crowd control
    HoJung Cho
    Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, Maryland, United States of America
    PLoS Biol 5:e302. 2007
    ..It suggests that this phenomenon can play a critical role in bacterial biofilm initiation and development of other complex multicellular bacterial super-structures, including those implicated in infectious diseases...
  4. ncbi request reprint Optofluidic 1x4 switch
    Alex Groisman
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 0374, USA
    Opt Express 16:13499-508. 2008
    ..The insertion loss was <2.5dB, the extinction ratio was >9.8dB, and the response time was 55 ms. The same basic design can be used to build optofluidic switches with more than 4 outputs...
  5. ncbi request reprint Generation of complex concentration profiles in microchannels in a logarithmically small number of steps
    Kyle Campbell
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
    Lab Chip 7:264-72. 2007
    ....
  6. pmc Innate non-specific cell substratum adhesion
    William F Loomis
    Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
    PLoS ONE 7:e42033. 2012
    ..Since glycoproteins are prevalent components of the surface of most cells, innate adhesion may be a common cellular property that has been overlooked...
  7. doi request reprint Incoherent feedforward control governs adaptation of activated ras in a eukaryotic chemotaxis pathway
    Kosuke Takeda
    Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
    Sci Signal 5:ra2. 2012
    ..Furthermore, these results are consistent with a local excitation, global inhibition mechanism for gradient sensing, possibly with a Ras guanosine triphosphatase-activating protein acting as a global inhibitor...
  8. pmc Gradient sensing in defined chemotactic fields
    Monica Skoge
    Division of Biological Sciences, University of California, La Jolla, CA 92093, USA
    Integr Biol (Camb) 2:659-68. 2010
    ..Correlation of the size and persistence of RasGTP patches with extension of pseudopods may set the rules for understanding how the signal transduction mechanisms convert a weak external signal to a strong directional bias...
  9. pmc High refractive index silicone gels for simultaneous total internal reflection fluorescence and traction force microscopy of adherent cells
    Edgar Gutierrez
    Department of Physics, University of California San Diego, La Jolla, California, United States of America
    PLoS ONE 6:e23807. 2011
    ..Here we apply high-refractive-index silicone gels to perform TIRF microscopy on substrates with a wide range of physiological elastic moduli and simultaneously measure traction forces exerted by cells on the substrate...
  10. pmc Visualizing a one-way protein encounter complex by ultrafast single-molecule mixing
    Yann Gambin
    Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
    Nat Methods 8:239-41. 2011
    ..The method also enabled analysis of rapid dissociation and unfolding of weakly bound complexes triggered by massive dilution...
  11. pmc Generation of oxygen gradients with arbitrary shapes in a microfluidic device
    Micha Adler
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, MC 0374, La Jolla, CA 92093, USA
    Lab Chip 10:388-91. 2010
    ..The system can be used to study directed migration of cells and the development of cell and tissue cultures under gradients of oxygen...
  12. pmc 'Slings' enable neutrophil rolling at high shear
    Prithu Sundd
    Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, USA
    Nature 488:399-403. 2012
    ..Each sling effectively lays out a cell-autonomous adhesive substrate in front of neutrophils rolling at high shear stress during inflammation...
  13. pmc An easy to assemble microfluidic perfusion device with a magnetic clamp
    Eugene Tkachenko
    Department of Medicine, University of California, San Diego, 9500 Gilman Drive, MC 0726, La Jolla, CA 92093, USA
    Lab Chip 9:1085-95. 2009
    ..The magnetic clamp can be closed with minimal mechanical perturbation to cells on the substrate and used with a variety of microfluidic chips for experiments with adherent and non-adherent cells...
  14. doi request reprint Fine temporal control of the medium gas content and acidity and on-chip generation of series of oxygen concentrations for cell cultures
    Mark Polinkovsky
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, MC 0374, La Jolla, CA 92093, USA
    Lab Chip 9:1073-84. 2009
    ..The proposed devices and technology can be used in research on bacteria and yeast under microaerobic conditions and on mammalian cells under hypoxia...
  15. pmc Studies of bacterial aerotaxis in a microfluidic device
    Micha Adler
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, MC 0374, La Jolla, CA 92093, USA
    Lab Chip 12:4835-47. 2012
    ..coli cells do not congregate at some intermediate level of [O(2)], but rather prefer the highest accessible [O(2)]. The presented technology can be applied to studies of aerotaxis of other aerobic and microaerobic bacteria...
  16. pmc Microfluidic device for single-molecule experiments with enhanced photostability
    Edward A Lemke
    Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
    J Am Chem Soc 131:13610-2. 2009
    ..Rapid buffer exchange in a laminar sheath flow followed by optical interrogation minimizes surface-sample contacts and allows the in situ addition and combination of other reagents...
  17. doi request reprint Ultrafast microfluidic mixer with three-dimensional flow focusing for studies of biochemical kinetics
    Yann Gambin
    Department of Molecular Biology, The Scripps Research Institute, 10550 N Torrey Pines Rd, La Jolla, CA 92037, USA
    Lab Chip 10:598-609. 2010
    ..Unlike previous ultrafast laminar mixers, which were machined in hard materials, the present microfluidic device is made of a single cast of poly(dimethylsiloxane), PDMS, and is thus simpler and less expensive to manufacture...
  18. pmc Measurements of elastic moduli of silicone gel substrates with a microfluidic device
    Edgar Gutierrez
    Department of Physics, University of California San Diego, La Jolla, California, United States of America
    PLoS ONE 6:e25534. 2011
    ..This work can lead to broader use of silicone gels in the cell biology laboratory and to improved repeatability and accuracy of cell traction force microscopy and rigidity sensing experiments...
  19. pmc Live cell imaging of paxillin in rolling neutrophils by dual-color quantitative dynamic footprinting
    Prithu Sundd
    Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
    Microcirculation 18:361-72. 2011
    ..However, elucidating the role of specific proteins in addition to topography requires simultaneous visualization of two fluorochromes...
  20. ncbi request reprint Perfusion in microfluidic cross-flow: separation of white blood cells from whole blood and exchange of medium in a continuous flow
    Virginia VanDelinder
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
    Anal Chem 79:2023-30. 2007
    ..The proposed technique of separation by perfusion in continuous cross-flow could be used to enrich rare populations of cells based on differences in size, shape, and deformability...
  21. pmc Protein kinase A governs a RhoA-RhoGDI protrusion-retraction pacemaker in migrating cells
    Eugene Tkachenko
    Department of Medicine, University of California San Diego, 9500 Gilman Drive, Mail Code 0726, La Jolla, California 92093, USA
    Nat Cell Biol 13:660-7. 2011
    ..Thus, cooperation between PKA, RhoA and RhoGDI forms a pacemaker that governs the morphodynamic behaviour of migrating cells...
  22. ncbi request reprint Microtargeted gene silencing and ectopic expression in live embryos using biolistic delivery with a pneumatic capillary gun
    Orit Shefi
    Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093 0376, USA
    J Neurosci 26:6119-23. 2006
  23. pmc Microwell devices with finger-like channels for long-term imaging of HIV-1 expression kinetics in primary human lymphocytes
    Brandon S Razooky
    Department of Chemistry and Biochemistry, University of California, San Diego, CA 92023, USA
    Lab Chip 12:4305-12. 2012
    ..The proposed devices offer a simple, robust approach to long-term single-cell studies of environmentally sensitive primary lymphocytes...
  24. pmc High-resolution temperature-concentration diagram of alpha-synuclein conformation obtained from a single Förster resonance energy transfer image in a microfluidic device
    Virginia VanDelinder
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, MC 0374, La Jolla, California 92093, USA
    Anal Chem 81:6929-35. 2009
    ..The microfluidic device can potentially be used to study other biomolecular and soft-matter systems...
  25. pmc External and internal constraints on eukaryotic chemotaxis
    Danny Fuller
    Cell and Developmental Biology, Division of Biological Sciences, Department of Physics, and Center for Theoretical Biological Physics, University of California, La Jolla, CA 92093, USA
    Proc Natl Acad Sci U S A 107:9656-9. 2010
    ....
  26. pmc Integrin-mediated protein kinase A activation at the leading edge of migrating cells
    Chinten J Lim
    Department of Medicine, University of California San Diego, La Jolla, CA 92093 0726, USA
    Mol Biol Cell 19:4930-41. 2008
    ..In sum, we have visualized compartment-specific PKA activation in migrating cells and used it to reveal that adhesion-mediated localized activation of PKA is an early step in directional cell migration...
  27. doi request reprint Bioluminescent response of individual dinoflagellate cells to hydrodynamic stress measured with millisecond resolution in a microfluidic device
    Michael I Latz
    Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093 0202, USA
    J Exp Biol 211:2865-75. 2008
    ....
  28. pmc Microfluidic devices for studies of shear-dependent platelet adhesion
    Edgar Gutierrez
    Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
    Lab Chip 8:1486-95. 2008
    ..Because of small sample volumes required, the devices could be employed in research with genetically-modified model organisms and for adhesion tests in clinical settings with blood from neonates...
  29. ncbi request reprint Quantitative measurements of the strength of adhesion of human neutrophils to a substratum in a microfluidic device
    Edgar Gutierrez
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
    Anal Chem 79:2249-58. 2007
    ..The proposed device and assay could be used to assess the state of activation of neutrophils in human blood with a potential application to diagnostics of inflammation...
  30. pmc Linear conversion of pressure into concentration, rapid switching of concentration, and generation of linear ramps of concentration in a microfluidic device
    Micha Adler
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, MC 0374, La Jolla, California 92093, USA
    Biomicrofluidics 6:24109-2410916. 2012
    ..The use of chaotic vs. laminar mixers is discussed in the context of microfluidic devices providing rapid switching and generating temporal waves of concentration...
  31. pmc Bound attractant at the leading vs. the trailing edge determines chemotactic prowess
    Paul Herzmark
    Departments of Cellular and Molecular Pharmacology, University of California, 600 16th Street, San Francisco, CA 94158, USA
    Proc Natl Acad Sci U S A 104:13349-54. 2007
    ....
  32. pmc Acute drug treatment in the early C. elegans embryo
    Ana Carvalho
    Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California, United States of America
    PLoS ONE 6:e24656. 2011
    ..This method should also open new avenues of investigation by allowing profiling and specificity-testing of inhibitors through comparison with genome-wide phenotypic datasets...
  33. ncbi request reprint High-throughput and high-resolution flow cytometry in molded microfluidic devices
    Claire Simonnet
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
    Anal Chem 78:5653-63. 2006
    ..The achieved resolution is comparable to that of still micrographs. This high-resolution device could be used for analysis of morphology and fluorescence distribution in cells in continuous flow...
  34. ncbi request reprint Separation of plasma from whole human blood in a continuous cross-flow in a molded microfluidic device
    Virginia VanDelinder
    Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
    Anal Chem 78:3765-71. 2006
    ....
  35. pmc Localized alpha4 integrin phosphorylation directs shear stress-induced endothelial cell alignment
    Lawrence E Goldfinger
    Sol Sherry Thrombosis Research Center and Department of Anatomy and Cell Biology, Temple University School of Medicine, 3400 N Broad Street, OMS 415, Philadelphia, PA 19140, USA
    Circ Res 103:177-85. 2008
    ..We thereby show that shear-induced PKA-dependent alpha4 integrin phosphorylation at the downstream edge of endothelial cells promotes localized Rac1 activation, which in turn directs cytoskeletal alignment in response to shear stress...