Oregon Green

The potential of using extrinsic (fluorescent) probes for monitoring the initial stages of oxidation was explored for the photo-oxidation of a UV-cured aliphatic polyurethane-acrylate-based adhesive [68]. The two probes investigated were p-dimethylamino salicylic acid (p-DASA) and 2, 7 -difluorescein (Oregon Green... 

Alternatively, proteins can be labeled selectively using amine-reactive dyes. Particularly, cysteine and lysines can be modified covalently with a variety of commercially available fluorophores including Texas Red, Oregon Green, and Cy3 [19] (see also Chapter 6 for small molecule FRET probes, and Chapter 12 depicting a variety... 

Dendrimers bearing certain fluorescent molecules attached on their periphery have been shown to be environmentally sensitive probes for the presence of certain metal ions or to changes in pH (Balzani et al., 2000 Paola et al., 2005). In addition, PAMAM dendrimers modified with the relatively hydrophobic dye Oregon Green 488 were shown to be a more effective transfection agent for anti-sense oligonucleotides than the dendrimer alone-plus the complex could be tracked within the cell due to the fluorescence of the dye (Yoo and Juliano, 2000). 

Figure 5. Fluorescence of collagen IV conjugated with Oregon Green 488 (Molecular Probes, Eugene, OR, USA.) spontaneously adsorbed to unmodified polyethylene foils (A) or polyethylene modified with 1014 0+ ions/cm at the energy of 30 keV (B). Collagen was diluted in phosphate-buffered saline to the concentration of 0.02 mg/ml (10 pg/cm ) and incubated with the foils for 24 h at room temperature. For auto fluorescence control.

Fluorochromes have been introduced that offer excitation and emission spectra similar to those of fluorescein, but that overcome some of fluorescein s limitations. BODIPY FL has a short Stokes shift, but offers higher fluorescence intensity, and is claimed to be more photostabile and less pH-sensitive than fluorescein. Oregon Green 488 and the newly introduced Alexa 488 fluorochromes have spectra nearly identical to those of fluorescein, but are considerably more photostabile, and produce less quenching of fluorescence with higher numbers of fluorochromes per antibody than does fluorescein. 

Green 488 carboxylic acid, Cascade Blue hydrazide, FQ-labeled aspartic acid, CBQCA-labeled serine and tyrosine, GFP, TAMRA-labeled 20-mer oligonucleotide, and fluorescently labeled PS particles see Figure 5.20). This focusing effect leads to a pre-concentration factor of 10,000 or greater (from 8 nM to 90 dM for Oregon Green) [597]. 

Several fluorescent labeling dyes are commercially available (Alexa series, Oregon green, Rhodamine and Cyanine dyes, etc.). They are all characterized by the presence of double bonds on every other carbon atom of a cyclic structure, containing the electron that once on excitation emitted fluorescent light. The cyanine dyes are the most widely used at the moment. They are bright, easily added to the nucleotides, stable to photo-bleaching and with a Stokes shift value of about 20 nm. The cyanine dyes used in microarray analysis are Cy3 (absorption at 550 nm and emission at 570 nm) and Cy5 (absorption at 649 nm and emission at 670 nm) that are already available as phosphoramidite derivatives. 

Hutchinson, J. University of Oregon, Green Chemistry Program, http //darkwing.uoregon.edu/ hutchlab/ greenchem/index.html... 

Figure 6.6. Visualization with confocal microscopy of actin filaments of rabbit intestinal cells loaded with Oregon Green Phalloidin. Images show control (left position) and enterocytes incubated for 4 hours with palytoxin (central position) or ostreocin-D (right position). Reproduced with permission from Ares et al. 2005.

Note Cellular model was intestinal cells. The actin filaments specific fluorescent marker, Oregon green phalloidin, detected with laser-scaiming cytometry allowed to quantify the microfilaments in rabbit intestinal cells... 

A sample purified of an Ostreopsis ovata extract was lately assayed on actin cytoskeleton of isolated rabbit intestinal cells by Botana s group. The measure of a fluorescent dye bound specifically to actin filaments (Oregon green 514-phalloidin) showed that Ostreopsis ovata toxin also interfered the cytoskeleton as occurred in the two previous cases (Table 6.4). In addition, activity on membrane potential of neuroblastoma cells was studied through the fluorescent probe bis-oxonol. The purified extract displayed a depolarizing effect (the value of relative fluorescence obtained at 350 seconds for cells exposed to the sample was 1.49 0.12 versus control) also similar to palytoxin and ostreocin-D. Therefore, although these studies only shed very preliminary information abont the toxic compound produced by Ostreopsis ovata, they appear to point out some link between its cellular targets and those identified for palytoxin and ostreocin-D in these studies. 

Figure 17.3. Neuroblastoma cells (BE(2)-M17 cell line) treated with azasplracld-1 (50 nM) for 48 hours show a rearrangement of their microfilament cytoskeleton and adopt a round morphology compared to the more flattened controls. (A) Carrier control (DMSO). (B) Azasplracld-1. MIcrofllaments (F-actIn) were labelled with Oregon Green Phalloldin (Molecular Probes) and pictures were taken using a Nikon Eclipse TE2000-E confocal microscope.

Zeglis BM, Barton JK. A mismatch-selective bifunctional rhodium-Oregon Green conjugate a fluorescent probe for mismatched DNA. J. Am. Chem. Soc. 2006 128 5654-5655. 

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