The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Shashi K. Murthy - One of the best experts on this subject based on the ideXlab platform.

  • Perspective on microfluidic Cell Separation: a solved problem?
    Analytical chemistry, 2014
    Co-Authors: Brian D. Plouffe, Shashi K. Murthy
    Abstract:

    The purification and sorting of Cells using microfluidic methodologies has been a remarkably active area of research over the past decade. Much of the scientific and technological work associated with microfluidic Cell Separation has been driven by needs in clinical diagnostics and therapeutic monitoring, most notably in the context of circulating tumor Cells. The last several years have seen advances in a broad range of Separation modalities ranging from miniaturized analogs of established techniques such as fluorescence- and magnetic-activated Cell sorting (FACS and MACS, respectively), to more specialized approaches based on affinity, dielectrophoretic mobility, and inertial properties of Cells. With several of these technologies nearing commercialization, there is a sense that the field of microfluidic Cell Separation has achieved a high level of maturity over an unusually short span of time. In this Perspective, we set the stage by describing major scientific and technological advances in this field ...

  • Stem Cell Separation Technologies.
    Current opinion in chemical engineering, 2013
    Co-Authors: Beili Zhu, Shashi K. Murthy
    Abstract:

    Stem Cell therapy and translational stem Cell research require large-scale supply of stem Cells at high purity and viability, thus leading to the development of stem Cell Separation technologies. This review covers key technologies being applied to stem Cell Separation, and also highlights exciting new approaches in this field. First, we will cover conventional Separation methods that are commercially available and have been widely adapted. These methods include fluorescence-activated Cell sorting (FACS), magnet-activated Cell sorting (MACS), preplating, conditioned expansion media, density gradient centrifugation, field flow fractionation (FFF), and dielectrophoresis (DEP). Next, we will introduce emerging novel methods that are currently under development. These methods include improved aqueous two-phase system, systematic evolution of ligands by exponential enrichment (SELEX), and various types of microfluidic platforms. Finally, we will discuss the challenges and directions toward future breakthroughs for stem Cell isolation. Advancing stem Cell Separation techniques will be essential for clinical and research applications of stem Cells.

  • Micro- and nanotechnology in Cell Separation.
    International journal of nanomedicine, 2006
    Co-Authors: Milica Radisic, Rohin K. Iyer, Shashi K. Murthy
    Abstract:

    This review describes recent work in Cell Separation using micro- and nanoscale technologies. These devices offer several advantages over conventional, macroscale Separation systems in terms of sample volumes, low cost, portability, and potential for integration with other analytical techniques. More importantly, and in the context of modern medicine, these technologies provide tools for point-of-care diagnostics, drug discovery, and chemical or biological agent detection. This review describes work in five broad categories of Cell Separation based on (1) size, (2) magnetic attraction, (3) fluorescence, (4) adhesion to surfaces, and (5) new emerging technologies. The examples in each category were selected to illustrate Separation principles and technical solutions as well as challenges facing this rapidly emerging field.

Tetsuji Yamaoka - One of the best experts on this subject based on the ideXlab platform.

  • Antibody-Immobilized Column for Quick Cell Separation Based on Cell Rolling
    Biotechnology progress, 2010
    Co-Authors: Atsushi Mahara, Tetsuji Yamaoka
    Abstract:

    Cell Separation using methodological standards that ensure high purity is a very important step in Cell transplantation for regenerative medicine and for stem Cell research. A Separation protocol using magnetic beads has been widely used for Cell Separation to isolate negative and positive Cells. However, not only the surface marker pattern, e.g., negative or positive, but also the density of a Cell depends on its developmental stage and differentiation ability. Rapid and label-free Separation procedures based on surface marker density are the focus of our interest. In this study, we have successfully developed an antiCD34 antibody-immobilized Cell-rolling column, that can separate Cells depending on the CD34 density of the Cell surfaces. Various conditions for the Cell-rolling column were optimized including graft copolymerization, and adjustment of the column tilt angle, and medium flow rate. Using CD34-positive and -negative Cell lines, the Cell Separation potential of the column was established. We observed a difference in the rolling velocities between CD34-positive and CD34-negative Cells on antibody-immobilized microfluidic device. Cell Separation was achieved by tilting the surface 20 degrees and the increasing medium flow. Surface marker characteristics of the isolated Cells in each fraction were analyzed using a Cell-sorting system, and it was found that populations containing high density of CD34 were eluted in the delayed fractions. These results demonstrate that Cells with a given surface marker density can be continuously separated using the Cell rolling column.

  • Antibody‐immobilized column for quick Cell Separation based on Cell rolling
    Biotechnology Progress, 2009
    Co-Authors: Atsushi Mahara, Tetsuji Yamaoka
    Abstract:

    Cell Separation using methodological standards that ensure high purity is a very important step in Cell transplantation for regenerative medicine and for stem Cell research. A Separation protocol using magnetic beads has been widely used for Cell Separation to isolate negative and positive Cells. However, not only the surface marker pattern, e.g., negative or positive, but also the density of a Cell depends on its developmental stage and differentiation ability. Rapid and label-free Separation procedures based on surface marker density are the focus of our interest. In this study, we have successfully developed an antiCD34 antibody-immobilized Cell-rolling column, that can separate Cells depending on the CD34 density of the Cell surfaces. Various conditions for the Cell-rolling column were optimized including graft copolymerization, and adjustment of the column tilt angle, and medium flow rate. Using CD34-positive and -negative Cell lines, the Cell Separation potential of the column was established. We observed a difference in the rolling velocities between CD34-positive and CD34-negative Cells on antibody-immobilized microfluidic device. Cell Separation was achieved by tilting the surface 20 degrees and the increasing medium flow. Surface marker characteristics of the isolated Cells in each fraction were analyzed using a Cell-sorting system, and it was found that populations containing high density of CD34 were eluted in the delayed fractions. These results demonstrate that Cells with a given surface marker density can be continuously separated using the Cell rolling column. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010

Venkatesan Sundaresan - One of the best experts on this subject based on the ideXlab platform.

  • The Arabidopsis myc/bHLH gene ALCATRAZ enables Cell Separation in fruit dehiscence
    Current biology : CB, 2001
    Co-Authors: Sarojam Rajani, Venkatesan Sundaresan
    Abstract:

    Abstract Background: Several processes of plant development, such as abscission, pollen release, fruit dehiscence, and seed dispersal, require organs or tissues to physically disassociate or split open. Due to the immobility of plant Cells, these processes occur through coordinated mechanisms of Cell Separation that are not found in animals. Arabidopsis produces dry dehiscent fruits (siliques) making it a convenient system for the genetic study of Cell Separation associated with dehiscence. Results: We describe here a novel mutation in Arabidopsis called alcatraz ( alc ), which prevents dehiscence of fruit by specifically blocking the Separation of the valve Cells from the replum. The ALC gene is shown to encode a protein related to the myc/bHLH family of transcription factors and is expressed in the valve margins of the silique, which is the site of Cell Separation during dehiscence. Detailed studies using TEM indicates that ALC enables Cell Separation in Arabidopsis fruit dehiscence by promoting the differentiation of a strip of labile nonlignified Cells sandwiched between layers of lignified Cells. Transgenic plants expressing antisense or dominant-negative ALC are defective in silique dehiscence. Conclusions: Cell Separation in fruit dehiscence requires a specialized Cell layer which is nonlignified and capable of autolysis, specified by a myc/bHLH protein encoded by ALC . These findings may have relevance to other processes requiring Cell Separation, as well as for the practical design of crops with reduced seed losses.

  • the arabidopsis myc bhlh gene alcatraz enables Cell Separation in fruit dehiscence
    Current Biology, 2001
    Co-Authors: Sarojam Rajani, Venkatesan Sundaresan
    Abstract:

    Abstract Background: Several processes of plant development, such as abscission, pollen release, fruit dehiscence, and seed dispersal, require organs or tissues to physically disassociate or split open. Due to the immobility of plant Cells, these processes occur through coordinated mechanisms of Cell Separation that are not found in animals. Arabidopsis produces dry dehiscent fruits (siliques) making it a convenient system for the genetic study of Cell Separation associated with dehiscence. Results: We describe here a novel mutation in Arabidopsis called alcatraz ( alc ), which prevents dehiscence of fruit by specifically blocking the Separation of the valve Cells from the replum. The ALC gene is shown to encode a protein related to the myc/bHLH family of transcription factors and is expressed in the valve margins of the silique, which is the site of Cell Separation during dehiscence. Detailed studies using TEM indicates that ALC enables Cell Separation in Arabidopsis fruit dehiscence by promoting the differentiation of a strip of labile nonlignified Cells sandwiched between layers of lignified Cells. Transgenic plants expressing antisense or dominant-negative ALC are defective in silique dehiscence. Conclusions: Cell Separation in fruit dehiscence requires a specialized Cell layer which is nonlignified and capable of autolysis, specified by a myc/bHLH protein encoded by ALC . These findings may have relevance to other processes requiring Cell Separation, as well as for the practical design of crops with reduced seed losses.

Feifei Long - One of the best experts on this subject based on the ideXlab platform.

  • Automated Microfluidic Instrument for Label-Free and High-Throughput Cell Separation.
    Analytical chemistry, 2018
    Co-Authors: Xinjie Zhang, Zhixian Zhu, Nan Xiang, Feifei Long
    Abstract:

    Microfluidic technologies for Cell Separation were reported frequently in recent years. However, a compact microfluidic instrument enabling thoroughly automated Cell Separation is still rarely reported until today due to the difficult hybrid between the macrosized fluidic control system and the microsized microfluidic device. In this work, we propose a novel and automated microfluidic instrument to realize size-based Separation of cancer Cells in a label-free and high-throughput manner. Briefly, the instrument is equipped with a fully integrated microfluidic device and a set of robust fluid-driven and control units, and the instrument functions of precise fluid infusion and high-throughput Cell Separation are guaranteed by a flow regulatory chip and two Cell Separation chips which are the key components of the microfluidic device. With optimized control programs, the instrument is successfully applied to automatically sort human breast adenocarcinoma Cell line MCF-7 from 5 mL of diluted human blood with a high recovery ratio of ∼85% within a rapid processing time of ∼23 min. We envision that our microfluidic instrument will be potentially useful in many biomedical applications, especially Cell Separation, enrichment, and concentration for the purpose of Cell culture and analysis.

  • Automated Microfluidic Instrument for Label-Free and High-Throughput Cell Separation
    2018
    Co-Authors: Xinjie Zhang, Zhixian Zhu, Nan Xiang, Feifei Long
    Abstract:

    Microfluidic technologies for Cell Separation were reported frequently in recent years. However, a compact microfluidic instrument enabling thoroughly automated Cell Separation is still rarely reported until today due to the difficult hybrid between the macrosized fluidic control system and the microsized microfluidic device. In this work, we propose a novel and automated microfluidic instrument to realize size-based Separation of cancer Cells in a label-free and high-throughput manner. Briefly, the instrument is equipped with a fully integrated microfluidic device and a set of robust fluid-driven and control units, and the instrument functions of precise fluid infusion and high-throughput Cell Separation are guaranteed by a flow regulatory chip and two Cell Separation chips which are the key components of the microfluidic device. With optimized control programs, the instrument is successfully applied to automatically sort human breast adenocarcinoma Cell line MCF-7 from 5 mL of diluted human blood with a high recovery ratio of ∼85% within a rapid processing time of ∼23 min. We envision that our microfluidic instrument will be potentially useful in many biomedical applications, especially Cell Separation, enrichment, and concentration for the purpose of Cell culture and analysis

Atsushi Mahara - One of the best experts on this subject based on the ideXlab platform.

  • Antibody-Immobilized Column for Quick Cell Separation Based on Cell Rolling
    Biotechnology progress, 2010
    Co-Authors: Atsushi Mahara, Tetsuji Yamaoka
    Abstract:

    Cell Separation using methodological standards that ensure high purity is a very important step in Cell transplantation for regenerative medicine and for stem Cell research. A Separation protocol using magnetic beads has been widely used for Cell Separation to isolate negative and positive Cells. However, not only the surface marker pattern, e.g., negative or positive, but also the density of a Cell depends on its developmental stage and differentiation ability. Rapid and label-free Separation procedures based on surface marker density are the focus of our interest. In this study, we have successfully developed an antiCD34 antibody-immobilized Cell-rolling column, that can separate Cells depending on the CD34 density of the Cell surfaces. Various conditions for the Cell-rolling column were optimized including graft copolymerization, and adjustment of the column tilt angle, and medium flow rate. Using CD34-positive and -negative Cell lines, the Cell Separation potential of the column was established. We observed a difference in the rolling velocities between CD34-positive and CD34-negative Cells on antibody-immobilized microfluidic device. Cell Separation was achieved by tilting the surface 20 degrees and the increasing medium flow. Surface marker characteristics of the isolated Cells in each fraction were analyzed using a Cell-sorting system, and it was found that populations containing high density of CD34 were eluted in the delayed fractions. These results demonstrate that Cells with a given surface marker density can be continuously separated using the Cell rolling column.

  • Antibody‐immobilized column for quick Cell Separation based on Cell rolling
    Biotechnology Progress, 2009
    Co-Authors: Atsushi Mahara, Tetsuji Yamaoka
    Abstract:

    Cell Separation using methodological standards that ensure high purity is a very important step in Cell transplantation for regenerative medicine and for stem Cell research. A Separation protocol using magnetic beads has been widely used for Cell Separation to isolate negative and positive Cells. However, not only the surface marker pattern, e.g., negative or positive, but also the density of a Cell depends on its developmental stage and differentiation ability. Rapid and label-free Separation procedures based on surface marker density are the focus of our interest. In this study, we have successfully developed an antiCD34 antibody-immobilized Cell-rolling column, that can separate Cells depending on the CD34 density of the Cell surfaces. Various conditions for the Cell-rolling column were optimized including graft copolymerization, and adjustment of the column tilt angle, and medium flow rate. Using CD34-positive and -negative Cell lines, the Cell Separation potential of the column was established. We observed a difference in the rolling velocities between CD34-positive and CD34-negative Cells on antibody-immobilized microfluidic device. Cell Separation was achieved by tilting the surface 20 degrees and the increasing medium flow. Surface marker characteristics of the isolated Cells in each fraction were analyzed using a Cell-sorting system, and it was found that populations containing high density of CD34 were eluted in the delayed fractions. These results demonstrate that Cells with a given surface marker density can be continuously separated using the Cell rolling column. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010