scholarly journals Fluorescence background discrimination by prebleaching.

1979 ◽  
Vol 27 (1) ◽  
pp. 96-101 ◽  
Author(s):  
T Hirschfeld
Keyword(s):  
Fluorescent Dyes ◽  
Fluorescence Decay ◽  
Free Form ◽  
Alternative Procedure ◽  
Background Fluorescence ◽  
Decay Lifetime ◽  
Fluorescent Molecules ◽  
Background Contrast

A number of electrooptical techniques are described that discriminate against background fluorescence in biologic staining, whether from sample background or unbound excess stain. These techniques are based on the fluorescent decay lifetime difference between bound stain and the sample background or between the bound stain its free form. The fluorescence decay lifetimes may be measured either directly or in a combination gated photometry scheme to substantially enhance the sample background contrast. An alternative procedure uses the photochemical bleaching of fluorescent dyes under intense exposure to time discriminate with higher selectivity, sensitivity and in a more convenient fashion between diverse fluorescent molecules.

Quantification of fluorescent molecules in heterogeneous media by use of the fluorescence decay amplitude analysis

1998 ◽  
Vol 8 (1) ◽  
pp. 27-34 ◽  
Author(s):  
G. E. Dobretsov ◽  
T. I. Syrejshchikova ◽  
Yu. A. Gryzunov ◽  
M. N. Yakimenko
Keyword(s):  
Heterogeneous Media ◽  
Decay Amplitude ◽  
Fluorescence Decay ◽  
Amplitude Analysis ◽  
Fluorescent Molecules

scholarly journals Cyanine Dyes for Photo-Thermal Therapy: A Comparison of Synthetic Liposomes and Natural Erythrocyte-Based Carriers

2021 ◽  
Vol 22 (13) ◽  
pp. 6914
Author(s):  
Giulia Della Della Pelle ◽  
Andrea Delgado Delgado López ◽  
Marina Salord Salord Fiol ◽  
Nina Kostevšek
Keyword(s):  
Optical Properties ◽  
Fluorescent Dyes ◽  
Temperature Stability ◽  
Membrane Vesicles ◽  
Cyanine Dyes ◽  
Free Form ◽  
New Era ◽  
Improved Stability ◽  
Photo Stability ◽  
Immunogenic Response

Cyanine fluorescent dyes are attractive diagnostic or therapeutic agents due to their excellent optical properties. However, in free form, their use in biological applications is limited due to the short circulation time, instability, and toxicity. Therefore, their encapsulation into nano-carriers might help overcome the above-mentioned issues. In addition to indocyanine green (ICG), which is clinically approved and therefore the most widely used fluorescent dye, we tested the structurally similar and cheaper alternative called IR-820. Both dyes were encapsulated into liposomes. However, due to the synthetic origin of liposomes, they can induce an immunogenic response. To address this challenge, we proposed to use erythrocyte membrane vesicles (EMVs) as “new era” nano-carriers for cyanine dyes. The optical properties of both dyes were investigated in different biological relevant media. Then, the temperature stability and photo-stability of dyes in free form and encapsulated into liposomes and EMVs were evaluated. Nano-carriers efficiently protected dyes from thermal degradation, as well as from photo-induced degradation. Finally, a hemotoxicity study revealed that EMVs seem less hemotoxic dye carriers than clinically approved liposomes. Herein, we showed that EMVs exhibit great potential as nano-carriers for dyes with improved stability and hemocompatibility without losing excellent optical properties.

scholarly journals Modeling the uptake of fluorescent molecules into 3D cellular spheroids

2019 ◽  
Vol 24 (5) ◽  
Author(s):  
Rokas Astrauskas ◽  
Feliksas Ivanauskas ◽  
Greta Jarockytė ◽  
Vitalijus Karabanovas ◽  
Ričardas Rotomskis
Keyword(s):  
Mathematical Models ◽  
Fluorescent Dyes ◽  
Rhodamine 6G ◽  
Diffusion Reaction ◽  
Fluorescent Label ◽  
System Of Differential Equations ◽  
Good Correspondence ◽  
Cellular Spheroids ◽  
Fluorescent Molecules ◽  
Reaction Equations

Three mathematical models were developed to analyze the dynamics of fluorescent dyes penetration into 3D cellular spheroids. Two fluorescent dyes were chosen to verify mathematical models: rhodamine 6G (R6G) as a small molecule, which can freely penetrate through the cells, and wheat germ agglutinin (WGA) conjugated with Alexa488 fluorescent label, which reacts with the cells plasma membrane, and its cellular penetration is significantly lower. Dye penetration and binding to cells were modeled with nonlinear diffusion–reaction equations. System of differential equations was solved using numerical methods, and good correspondence with physical experiment was shown. Diffusion coefficients in extracellular matrix were determined for both fluorescent dyes, and the influence of reactions parameters to WGA penetration was analyzed. Dynamics of dyes accumulation into cell spheroids were also determined.

scholarly journals Fluorescent characterization of amyloid deposits in the kidneys of mdx mice

2018 ◽  
Author(s):  
Valeriia Gusel'nikova ◽  
Olga Antimonova ◽  
Elena Fedorova ◽  
Mikhail Shavlovsky ◽  
Aleksandr Krutikov ◽  
...  
Keyword(s):  
Congo Red ◽  
Fluorescent Dyes ◽  
Fluorescent Dye ◽  
Fixation Method ◽  
Mdx Mice ◽  
Renal Amyloidosis ◽  
Positive Staining ◽  
Background Fluorescence ◽  
Amyloid Deposits ◽  
Mouse Tissues

Amyloidosis is a group of diseases that occurs when amyloid proteins are deposited in tissues and organs. The traditional way of identifying amyloid in tissue sections is staining with Congo red. However, this method has a number of limitations including background staining (background fluorescence), low fluorescence intensity and false-positive staining. Therefore, a complex of fluorescence-based methods should be applied to characterize tissue localization of amyloid deposits. The aim of this study was to identify amyloid deposits in the kidneys of dystrophin-deficient mdx mice using different fluorescent dyes. We examined 8 cases of renal amyloidosis in aged mdx mice. In all cases, we used traditional methods for amyloid detection (Congo red and Thioflavin T), as well as a new fluorescent dye, disodium salt of 2,7- (1-amino-4-sulfo-2-naphthylazo) fluorene (DSNAF). In our study, we confirmed the amyloid structure of protein deposits in kidneys of aging mdx mice by several fluorescence-based staining methods. We found that fixation method has profound effects on downstream staining procedures, and demonstrated that the application of specific fixative, zinc-ethanol-formaldehyde (ZEF), instead of traditional NBF allow to reduce the background fluorescence. We also illustrated the usefulness of novel fluorescent dye DSNAF for detection of amyloid deposits in mouse tissues. Our results confirmed the strong affinity and high specificity of this dye for amyloid fibrils. The verification of DSNAF for detecting amyloid in human tissues will provide a conclusion on the applicability of the developed staining method in clinical research practice.

scholarly journals The fluorescent dyes TO-PRO-3 and TOTO-3 iodide allow detection of microbial cells in soil samples without interference from background fluorescence

BioTechniques ◽  
2011 ◽  
Vol 51 (3) ◽  
Author(s):  
Ruth Henneberger ◽  
Debra Birch ◽  
Peter Bergquist ◽  
Malcolm Walter ◽  
Roberto Anitori
Keyword(s):  
Fluorescent Dyes ◽  
Soil Samples ◽  
Microbial Cells ◽  
Background Fluorescence

Fluorescence Decay Lifetime of Ultrafine CdS and ZnS Particles

1994 ◽  
Vol 11 (2) ◽  
pp. 127-128
Author(s):  
Xueping Li ◽  
Changyu Fan ◽  
Zhenzong Zhang ◽  
Xurui Xiao
Keyword(s):  
Fluorescence Decay ◽  
Decay Lifetime

Cover Picture: Imaging the Fluorescence Decay Lifetime of a Conjugated-Polymer Blend By Using a Scanning Near-Field Optical Microscope (Adv. Mater. 1/2007)

2007 ◽  
Vol 19 (1) ◽  
pp. NA-NA
Author(s):  
A. J. Cadby ◽  
R. Dean ◽  
C. Elliott ◽  
R. A. L. Jones ◽  
A. M. Fox ◽  
...  
Keyword(s):  
Polymer Blend ◽  
Conjugated Polymer ◽  
Near Field ◽  
Optical Microscope ◽  
Fluorescence Decay ◽  
Decay Lifetime

Fluorescence Decay of Pyrene in a Hydrogenated Pyrene Matrix

1979 ◽  
Vol 32 (2) ◽  
pp. 257
Author(s):  
CM Harris ◽  
BK Selinger
Keyword(s):  
Solid Solution ◽  
Fluorescence Decay ◽  
Decay Lifetime

Pyrene, 4,5-dihydropyrene and 4,5,9,10-tetrahydropyrene have been found to form a true solid solution over a range of composition. The measured fluorescence decay lifetime of pyrene in a hydrogenated pyrene matrix has been found to depend on the wavelength at which the emission is monitored, but not on the wavelength of excitation.

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