scholarly journals Lab-on-a-chip technologies for proteomic analysis from isolated cells

2008 ◽  
Vol 5 (suppl_2) ◽  
Author(s):  
H Sedgwick ◽  
F Caron ◽  
P.B Monaghan ◽  
W Kolch ◽  
J.M Cooper

Lab-on-a-chip systems offer a versatile environment in which low numbers of cells and molecules can be manipulated, captured, detected and analysed. We describe here a microfluidic device that allows the isolation, electroporation and lysis of single cells. A431 human epithelial carcinoma cells, expressing a green fluorescent protein-labelled actin, were trapped by dielectrophoresis within an integrated lab-on-a-chip device containing saw-tooth microelectrodes. Using these same trapping electrodes, on-chip electroporation was performed, resulting in cell lysis. Protein release was monitored by confocal fluorescence microscopy.

2000 ◽  
Vol 68 (2) ◽  
pp. 956-959 ◽  
Author(s):  
Derrick H. Lenz ◽  
Christine L. Weingart ◽  
Alison A. Weiss

ABSTRACT Previous studies have reported that phagocytosed Bordetella pertussis survives in human neutrophils. This issue has been reexamined. Opsonized or unopsonized bacteria expressing green fluorescent protein (GFP) were incubated with adherent human neutrophils. Phagocytosis was quantified by fluorescence microscopy, and the viability of phagocytosed bacteria was determined by colony counts following treatment with polymyxin B to kill extracellular bacteria. Only 1 to 2% of the phagocytosed bacteria remained viable. Opsonization with heat-inactivated immune serum reduced the amount of attachment and phagocytosis of the bacteria but did not alter survival rates. In contrast to previous reports, these data suggest that phagocytosed B. pertussis bacteria are killed by human neutrophils.


1999 ◽  
Vol 67 (12) ◽  
pp. 6695-6697 ◽  
Author(s):  
Stephan Köhler ◽  
Safia Ouahrani-Bettache ◽  
Marion Layssac ◽  
Jacques Teyssier ◽  
Jean-Pierre Liautard

ABSTRACT A gene fusion system based on plasmid pBBR1MCS and the expression of green fluorescent protein was developed for Brucella suis, allowing isolation of constitutive and inducible genes. Bacteria containing promoter fusions of chromosomal DNA togfp were visualized by fluorescence microscopy and examined by flow cytometry. Twelve clones containing gene fragments induced inside J774 murine macrophages were isolated and further characterized.


1999 ◽  
Vol 65 (4) ◽  
pp. 1769-1771 ◽  
Author(s):  
Bernard Dumas ◽  
Sylvie Centis ◽  
Nathalie Sarrazin ◽  
Marie-Thérèse Esquerré-Tugayé

ABSTRACT The 5′ noncoding region of clpg2, an endopolygalacturonase gene of the bean pathogenColletotrichum lindemuthianum, was fused to the coding sequence of a gene encoding a green fluorescent protein (GFP), and the construct was introduced into the fungal genome. Detection of GFP accumulation by fluorescence microscopy examination revealed thatclpg2 was expressed at the early stages of germination of the conidia and during appressorium formation both in vitro and on the host plant.


2000 ◽  
Vol 6 (S2) ◽  
pp. 838-839
Author(s):  
Richard M. Levenson

Autofluorescence , also known as adventitious fluorescence or background fluorescence, ofter poses a significant problem in many applications of fluorescence microscopy. It contributes to unwanted noise and can swamp the desired signal. Particularly difficult samples to image include many pathology specimen that have been processed using crosslinking fixatives (typically formaldehyde). This procedure dramatically increase the autofluorescence level, leading to bright, broad spectrum emissions, particularly from connective tissue components. Unprocessed plant tissue and neuronal tissue also have extremely high levels of endogenous autofluorescence that can make many convenient labeling strategies, including most (green fluorescent protein (GFP) labels, extremely problematic. Various solutions have been proposed for the reduction or elimination of autofluorescence. These include using narrow bandpass emission filters to try to isolate the desired fluorescence signal, the use of labels which can be excited at wavelengths that are much less likely to induce autofluorescence (moving the excitation towards the NIR is effective), and post-processing aldehyde-fixed samples with such reagents as sodium borohydride or toluidine blue to chemically suppress the autofluorescence signal.However, in many cases, these approaches are either infeasible or ineffective.


Luminescence ◽  
2013 ◽  
Vol 28 (4) ◽  
pp. 582-591 ◽  
Author(s):  
Katsunori Ogoh ◽  
Takashi Kinebuchi ◽  
Mariko Murai ◽  
Takeo Takahashi ◽  
Yoshihiro Ohmiya ◽  
...  

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