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Fluorescence Plate Reader (fluorescence + plate_reader)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Inkjet Printing of Luminescent CdTe Nanocrystal,Polymer Composites,

ADVANCED FUNCTIONAL MATERIALS, Issue 1 2007
E. Tekin
Abstract Inkjet printing is used to produce well-defined patterns of dots (with diameters of ca.,120,,m) that are composed of luminescent CdTe nanocrystals (NCs) embedded within a poly(vinylalcohol) (PVA) matrix. Addition of ethylene glycol (1,2,vol,%) to the aqueous solution of CdTe NCs suppresses the well-known ring-formation effect in inkjet printing leading to exceptionally uniform dots. Atomic force microscopy characterization reveals that in the CdTe NC films the particle,particle interaction could be prevented using inert PVA as a matrix. Combinatorial libraries of CdTe NC,PVA composites with variable NC sizes and polymer/NC ratios are prepared using inkjet printing. These libraries are subsequently characterized using a UV/fluorescence plate reader to determine their luminescent properties. Energy transfer from green-light-emitting to red-light-emitting CdTe NCs in the composite containing green- (2.6,nm diameter) and red-emitting (3.5,nm diameter) NCs are demonstrated. [source]

Immunoliposomes Sandwich Fluorometric Assay (ILSF) for Detection of Escherichia coli O157:H7

JOURNAL OF FOOD SCIENCE, Issue 6 2004
Sungsu Park
ABSTRACT: We report the development of automated flourometric immunoassay for the detection of Escherichia coli O157:H7, using antibody-directed liposomes (immunoliposomes) encapsulating fluorophore as an analytical reagent. Thiolated antibodies (anti- E. coli O157:H7) were coupled to malemide-tagged liposomes encapsulating dye. To automate the assay, a fluorescence plate reader was included in the assay system to detect fluorophore released from lysed liposomes in a microplate. The detection limit of the current assay with pure cultures of the serotype was about 104 colony-forming units (CFU)/mL. The assay can detect E. coli O157 in ground beef samples inoculated with as few as 0.8 CFU/mL after a 12-h enrichment. These results demonstrate the feasibility of using fluorophore-encapsulated immunoliposomes in a microtiter plate for the rapid and automated detection of molecules with multivalent antigenic sites. [source]

Ink-Jet Printing of Luminescent Ruthenium- and Iridium-Containing Polymers for Applications in Light-Emitting Devices

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 4 2005
Emine Tekin
Abstract Summary: Defined films of luminescent ruthenium(II) polypyridyl-poly(methyl methacrylate) (PMMA) and iridium(III) polypyridyl-polystyrene (PS) copolymers could be prepared by ink-jet printing. The copolymers were deposited on photoresist-patterned glass substrates. Films as thin as 120 nm could be printed with a roughness of 1 to 2%. In addition, the film thickness could be varied in a controlled way through the number of droplets deposited per unit area. The topography of the ink-jet printed films was analyzed utilizing an optical profilometer. The absorbance and emission spectra were measured using fast parallel UV-vis and fluorescence plate reader. Photo of the solutions of luminescent ruthenium (left) and iridium (right) containing polymers in a glass microtiter plate (top). The subsequently prepared films using ink-jet dispensing techniques are shown below. [source]

The use of small molecule high-throughput screening to identify inhibitors of the proteinase 3-NB1 interaction

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2010
M. Choi
Summary Anti-neutrophil cytoplasmic antibodies (ANCA) to proteinase 3 (PR3) are found in patients with small-vessel vasculitis. PR3-ANCA bind strongly to membrane PR3 (mPR3) that is presented by the NB1 receptor. We performed high-throughput screening using a small molecule library to identify compounds that inhibit PR3-NB1 binding. We established a human embryonic kidney (HEK293) cell-based system, where approximately 95 ± 2% of the NB1-transfected cells expressed the NB1 receptor on the cell surface. Addition of 0·1 µg/ml human PR3 to 104 NB1-expressing HEK293 cells resulted in PR3 binding that was detected by immunofluorescence using a fluorescence plate reader assay. We identified 13 of 20 000 molecules that inhibited PR3 binding by >70%. Seven of 13 substances showed reproducible inhibition in four additional validation experiments. Two selected compounds (27519 and 27549) demonstrated a dose-dependent inhibition over a range from 6·25 to 100 µM as measured by the plate reader assay. We used flow cytometry as a second assay, and found that both compounds reproducibly inhibited PR3 binding to NB1-transfected HEK293 cells at 50 µM (inhibition to 42 ± 4% with compound 27519 and to 47 ± 6% with compound 27549 compared to the dimethylsulphoxide control). Furthermore, compounds 27519 and 27549 also inhibited binding of exogenous PR3 to human neutrophils. In contrast, the compounds did not decrease mPR3 expression on resting neutrophils, but reduced the tumour necrosis factor-,-mediated mPR3 increase on NB1pos neutrophils when present continuously during the assay. The findings suggest that small inhibitory compounds provide a potential therapeutic tool to reduce mPR3 by preventing its binding to NB1. [source]