Streptavidin continued

Fig. 7 (continued) color indicates colocalized QD-AST1 and Sytol6. (b-e) Phase, fluorescence, and overlay images of A431 (b, c) and 3T3 (d, e) cells labeled using solutions of 0.5 nM QD-streptavidin (b, d) and 0.5 nM QD-AST1 (c, e). Scale bars 25 pm. (Adapted from [47])... 

Then, return to Subheading 3.1., step 15 and add more ABC solution or a labeled streptavidin compound. Continue on with the procedure from there. 

Fig. s.n On-line continuous-flow monitoring of biochemical interaction with (a) fluorescence and (b) MS SIM (m/z 390) detection. Fluorescein-biotin (96 nM), streptavidin (32 nM), 20-pL loop injections of 1000 nM biotin (n = 3). MS instrument Q-ToF2 (Waters) equipped with a Waters Z-spray electrospray (ESI) source. Point 1 Carrier pump, protein and reporter ligand pumps... 

Enzyme kinetics were evaluated in a PDMS-glass chip using a continuous-flow system. A biotinylated enzyme (HRP or (5-galactosidase) was coupled to streptavidin-coated beads via the amide coupling of an aminocaproyl spacer. These beads (15.5 pm) were retained by a weir in the chip. The channel wall was passivated by 1 mg/mL BSA. The apparent enzyme kinetic parameters were evaluated using the Lilly-Homby model, as developed for the packed-bed enzymatic reactor systems. It was found that the apparent Michaelis constant (Km) approached the tme Km value of the free enzyme at zero-flow rate of a homogeneous reaction [845]. 

An example of the immobilization on polystyrene beads is the bead-bed micro-ELISA system of Kitamori et al. [403]. The beads were coated with a capture antibody and loaded into the reaction channel of the ELISA microchip (Scheme 4.92a). Next, solutions containing antigen (Scheme 4.92b), a biotinylated secondary antibody (Scheme 4.92c) and a streptavidin-peroxidase conjugate were introduced into the channel (Scheme 4.92d). Finally, the substrate for peroxidase was continuously... 

For the procedure, add the biotinyl tyramide (Dupont NEN, Boston, MA Dako, Carpenteria, CA or Perkin Elmer, Life Science Research, Waltham, MA) solution in place of the DAB solution in Subheading 3.1, step 19 and incubate for 15 min. Rinse as in Subheading 3.1, step 16. Then, return to Subheading 3.1, step 15, and add more ABC solution, or a labeled streptavidin compound. Continue with the procedure from there. 

We also reported a concept for a sandwich immunoassay that is completely performed on-chip using streptavidin-coated beads as substrate [17]. The latter were electrostatically self-assembled on aminosilane micropattems at the bottom of a microfluidic channel. We used mouse IgG diluted in phosphate buffered saline (PBS) with 1% bovine serum albumin (BSA) solution as target antigen. The fluorescent sandwich immunocomplex was formed on the beads during the operation of the chip both in stop-flow and continuous flow modes. Target mouse IgG antigen could be detected down to a concentration of 15 ng/mL in stop-flow mode and 250 pg/mL in continuous flow mode, using only 1,300 nL of sample volume. 

Conceptual drawing of microflow stmctures within a microfluidic network for the particle crossover within microfluidic channels. It is possible to achieve the particle crossover from one to another fluid streams without losing particles into multiple parallel channels, (b) Schematic sketch of a representative example of continuous biosensing using the particle crossover mechanism. The concentration of biotinylated FITC molecules can be determined by measuring the fluorescence intensity of the biotinylated FITC bound streptavidin-coated 8-pm-diameter particle at the detection window using an epifluorescence microscope [5]... 

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