Colorimetric Immunological Paper-based Assay for Exosome Detection

Abstract This paper reports the development of colorimetric immunological paper-based assay for exosome detection. The paper-based device was fabricated with lamination technique for easy handling and create hydrophilic/hydrophobic region for analytical paper-based devices. Exosome-specific antibody was coated onto the paper-based devices as a biosensing platform to detect exosome sample from the cell culture media. This assay employed a colorimetric reaction which is followed by reaction between horseradish peroxidase (HRP) and 3,3’,5,5’-tetramethylbenzidine substrate (TMB). The colorimetric readout was qualitatively evaluated by naked eyes and was quantitatively assessed by image processing software. The result indicated that this assay faces many challenges. First, the exosome concentration may be inadequate to reach detectable range. Second, high background signal due to non-specific binding on the platform results in lack of sensitivity for exosome detection. Therefore, modification on the paper should promote protein binding for specific target and prevent non-specific binding to reduce the high background signal.

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Analysis of the 9th November 1990 flare

International Astronomical Union Colloquium ◽

10.1017/s025292110006454x ◽

2000 ◽

Vol 179 ◽

pp. 229-232

Author(s):

Anita Joshi ◽

Wahab Uddin

Keyword(s):

Image Processing ◽

Two Dimensional ◽

Temporal Behaviour ◽

Contour Maps ◽

Dimensional Measurements ◽

Processing Software ◽

Image Processing Software

AbstractIn this paper we present complete two-dimensional measurements of the observed brightness of the 9th November 1990Hαflare, using a PDS microdensitometer scanner and image processing software MIDAS. The resulting isophotal contour maps, were used to describe morphological-cum-temporal behaviour of the flare and also the kernels of the flare. Correlation of theHαflare with SXR and MW radiations were also studied.

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High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084624 ◽

1991 ◽

Vol 49 ◽

pp. 64-65

Author(s):

Marek Malecki ◽

James Pawley ◽

Hans Ris

Keyword(s):

Electron Microscopy ◽

High Pressure ◽

Low Voltage ◽

Culture Media ◽

Cell Structure ◽

Freeze Substitution ◽

Ice Crystal ◽

High Pressure Freezing ◽

Cell Culture Media ◽

Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

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Cell culture media: NMR approaches to evaluating quality and nutrient consumption

Planta Medica ◽

10.1055/s-0036-1596271 ◽

2016 ◽

Vol 81 (S 01) ◽

pp. S1-S381

Author(s):

KB Killday ◽

AS Freund ◽

C Fischer ◽

KL Colson

Keyword(s):

Cell Culture ◽

Culture Media ◽

Cell Culture Media ◽

Nutrient Consumption

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The Influence of Glycosylation on the Catalytic and Fibrinolytic Properties of Pro-Urokinase

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646314 ◽

1992 ◽

Vol 68 (05) ◽

pp. 539-544 ◽

Cited By ~ 22

Author(s):

Catherine Lenich ◽

Ralph Pannell ◽

Jack Henkin ◽

Victor Gurewich

Keyword(s):

Escherichia Coli ◽

Mammalian Cell ◽

Human Gene ◽

Culture Media ◽

Mammalian Cell Culture ◽

Glycosylation Site ◽

Clot Lysis ◽

Cell Culture Media ◽

E Coli ◽

The Uk

SummaryWe previously found that human pro-UK expressed in Escherichia coli is more active in fibrinolysis than recombinant human pro-UK obtained from mammalian cell culture media. To determine whether this difference is related to the lack of glycosylation of the E. coli product, we compared the activity of E. coli-derived pro-UK [(-)pro-UK] with that of a glycosylated pro-UK [(+)pro-UK] and of a mutant of pro-UK missing the glycosylation site at Asn-302 [(-) (302) pro-UK]. The latter two pro-UKs were obtained by expression of the human gene in a mammalian cell. The nonglycosylated pro-UKs were activated by plasmin more efficiently (≈2-fold) and were more active in clot lysis (1.5-fold) than the (+)pro-UK. Similarly, the nonglycosylated two-chain derivatives (UKs) were more active against plasminogen and were more rapidly inactivated by plasma inhibitors than the (+)UK.These findings indicate that glycosylation at Asn-302 influences the activity of pro-UK/UK and could be the major factor responsible for the enhanced activity of E. coli-derived pro-UK.

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