Fluorescent-labeled particles

TAT-peptide modified liposomes were prepared and cellular association and intracellular distribution of (double) fluorescently labelled particles were assessed by flow cytometry and confocal laser scanning microscopy. 

The stoichiometry of the recharged DNA/PLL/SPLL particles was studied using sucrose-gradient ultracentrifugation of fluorescently labeled polyion complexes in 25 mM HEPES buffer. Rhodamine-labeled DNA (Rh-DNA) and either fluorescein-labeled PLL (Fl-PLL) or SPLL (Fl-SPLL) were used to determine their relative amounts within DNA... 

Initially, it is necessary to select carefully the assay incubation time. With that aim, different batches of MIP particles (2.5 mg mL ) were incubated for between 0 and 18 h at room temperature in polypropylene tubes on a shaking table with 250 nmol L 1 of PAAP in the absence and in the presence of 166 pg mL 1 of penicillin G (in acetonitrile-water, 99 1), with 2 mL of a fluorescently labeled penicillin (PAAP) [36]. As shown in Fig. 5, binding to the CP was very low in comparison to that of the MIP and 7 h were required to achieve equilibria. 

To observe the flow, small spherical polystyrene particles of 50 nm radius which are fluorescently labeled, are added. To keep them dispersed they have sulfate groups on their surface. This leads to a zeta potential of —20 mV. How fast and in which direction do these particles move A good marker should move with the same speed as the liquid flow. Was it a good idea to use these particles as markers ... 

Fig. 7 An illustration of how molecules can enter cytosol after photochemical treatment (light first principle), (a) The photosensitizer (S) is endocytosed by the cells and when exposed to light the membranes of these vesicles will rupture and the contents (L) released into the cytosol, (b) Macromolecules that are administrated after the photochemical treatment will be endocytosed and end up in intact newly formed vesicles. These vesicles may then fuse with the photochemically damaged vesicles and the contents of the fused vesicles are released into the cytosol. The pictures at the bottom shows cells stained with fluorescently labelled dextran particles delivered before or after the photochemical treatment...

Motion analysis and particle tracking methods enable users to follow the movement over time of tagged particles, such as fluorescently labeled cell surface molecules, microtubules, nucleic acids, lipids, and other objects with subpixel resolution.287 These methods allow scientists to measure jc and y coordinates, velocity, mean displacement, mean vector length, and more. 

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]. 

Figure 9.8 Bilayers and a mixed monolayer of biotinylated and fluorescently labeled Cowpea mosaic virus (CPMV) particles on gold slides imaged via fluorescence microscopy The bilayers are shown on the left and the mixed monolayer on the right. A schematic representation of the CPMV layer...

Several configurations for the sensor are possible. An especially viable alternative would seem to be the competitive displacement of fluorescent label. Since this is an equilibrium, fouling or contamination of the surface should not alter the absolute result. Krull et al (75) have reported the reproducible immobilisation of a stable phospholipid membrane containing fluorophore in this context. Concurrent fluorescence polarisation measurements can offer the possibility of multidimensional analysis (76) and are in any case experiencing a rejuvenation of interest as a highly selective technique, when the effective molecular weight of the antibody is increased relative to the antigen, by immobilisation on a latex or metal particle (77)... 

---