Search PubMed⌕ Search

PubMed · 16351145

A scalable addressable positive-dielectrophoretic cell-sorting array.

Abstract

We present the first known implementation of a passive, scalable architecture for trapping, imaging, and sorting individual microparticles, including cells, using a positive dielectrophoretic (p-DEP) trapping array. Our array-based technology enables "active coverslips" where, when scaled, many individually held cells can be sorted based upon imaged spatial or temporally variant characteristics. Our design incorporates a unique "ring-dot" p-DEP trap geometry organized in a row/column array format. This trap design, implemented in a two-level metal process, provides strong and highly spatially localized holding fields enabling single-cell capture for all traps in the array. We release individual trapped microparticles during sorting using a passive transistor-independent approach where we electrically ground the row and column electrodes associated with specific traps in the array. The demand for chip-to-world electrical connections in our arrays scales proportionally with the square root of the number of traps in a given array, delivering a substantial improvement over prior designs. We demonstrate capture, holding, and release operations with both beads and cells in small arrays of this new architecture.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Brian M Taff, Joel Voldman. 2005-12-15. A scalable addressable positive-dielectrophoretic cell-sorting array.. https://doi.org/10.1021/ac0513616

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Prostaglandin E2 is a negative regulator on human plasmacytoid dendritic cells.

Prostaglandin E2 (PGE2), a major lipid derived from the metabolism of arachidonic acid, is an environmentally bioactive substance produced by inflammatory processes and acts as a cAMP up-regulator that plays an important role in immune responses. It has been reported that PGE2 has the ability to inhibit the production of interleukin-12 by myeloid dendritic cells (MDCs) and macrophages, and then induce preferential T helper type 2 (Th2) cell responses. However, little is known of the function of PGE2 for plasmacytoid dendritic cells (PDCs), which may contribute to the innate and adaptive immune response to viral infection, allergy and autoimmune diseases. In the present study, we compared the biological effect of PGE2 on human PDCs and MDCs. PGE2 caused the death of PDCs but MDCs survived. Furthermore, we found that, whereas PGE2 inhibited interferon-alpha production by PDCs in response to virus or cytosine-phosphate-guanosine, it inhibited interleukin-12 production by MDCs in response to lipopolysaccharide (LPS) or poly(I:C). Although both virus-stimulated PDCs and LPS-stimulated MDCs preferentially induced the development of interferon-gamma-producing Th1 cells, pretreatment with PGE2 led both DC subsets to attenuate their Th1-inducing capacity. These findings suggest that PGE2 represents a negative regulator on not only MDCs but also PDCs.

Cell Separation↗

Influence of swim-up time on the ratio of X- and Y-bearing spermatozoa.

OBJECTIVE: The objective was to examine the separation of X- and Y-bearing spermatozoa in a modified swim-up procedure using fluorescent in situ hybridization (FISH), and to find out the influence of swim-up time on the ratio of X- and Y-bearing spermatozoa. STUDY DESIGN: Prospective study. SETTING: Reproductive testing laboratory in a university hospital. PATIENTS: Normal spermatozoa samples were obtained from 10 volunteers by masturbation after sexual abstinence for 3-5 days. INTERVENTIONS: Spermatozoa were put into 18 tubes with 0.25 ml in each, then mixed with HTF medium and centrifuged for 5 min (400 x g). The supernatant was removed and discarded and 0.5 ml HTF was added slowly along the tube wall. Motile spermatozoa were collected after swimming up in different times (from 5 up to 150 min, with a total of 17 intervals). The X- and Y-bearing spermatozoa were determined using the FISH technique. The X/Y dual-color CEP probes that were marked by fluorescein isothiocyanate (FITC) and Texas red were applied to analyze the ratio of X- and Y-bearing spermatozoa. The FISH staining slides were analyzed under an immunofluorescence microscope. About 1000-1500 spermatozoa were counted per slide. MAIN OUTCOME MEASURES: The percentages of X- and Y-bearing spermatozoa were calculated. RESULTS: The study results suggested that the total ratio of hybridization was 98.33%. The ratio of X-bearing spermatozoa after swimming up for different amounts of time is 50.03 +/- 0.91% at 0 min, 50.45 +/- 2.06% after 15 min, 50.61 +/- 2.47% after 30 min, 50.16 +/- 2.67% after 60 min, 50.72 +/- 2.64% after 90 min, and 50.56 +/- 2.20% after 150 min. The statistical analysis showed that there were no significant differences among different swim-up times in the ratio of X-bearing spermatozoa. CONCLUSIONS: There was no significant effect of swim-up time on the ratios of X- and Y-bearing spermatozoa using a modified swim-up procedure. No direct evidence was found that the swim-up procedure for separating motile spermatozoa to use for either intrauterine insemination (IUI) or in vitro fertilization (IVF) would lead to an imbalance of boys and girls.

Cell Separation↗