Bromophenol blue monitoring

Ng and Assirelli have carried out a mixing study in batch stirred vessels with working volumes of 3 L to 20L using a fiber-optic UV-vis monitoring technique. Bromophenol blue sodium salt was used as a non-reactive tracer. The results on traditional Rushton turbines and 45° angled pitched blade turbines showed good agreement with a typical conductivity technique and a correlation proposed in literature. 

Solutions of indicators are out for pH measuring, but fhey are useful for monitoring some processes, such as tissue cultures (indicator phenol red) or electrophoresis (electrophoresis front and pH of sample indicator bromophenol blue). 

Once the solution is heated to dissolve the agarose, the solution is cooled momentarily and poured into a slab mold fitted at one end with a Teflon or plastic comb. After the solution polymerizes, the comb is removed to create wells into which the desired DNA or RNA samples will be applied. The gel is then transferred to an electrophoresis chamber and is completely covered with the same TAE or TBE buffer that was used to cast the gel. Next, the nucleic acid sample is mixed with a viscous buffer (30% glycerol) containing one or more tracking dyes that will be used to monitor the progress of the electrophoresis. Bromophenol blue dye will migrate at the same rate as a DNA molecule of about 500 base pairs, while xylene cyanole... 

Colored reagents to follow the appearance or the disappearance of a functional group have been widely used to monitor reactions in classical organic chemistry, particularly in TLC analysis. This technique has been successfully adapted to SPS for example, ninhydrin (118), bromophenol blue (119), nitrophenyl isothiocyanate-O-trityl (120), picric acid (121), and malachite green isothiocyanate (122) have all been used to show the presence or the absence of free resin-bound amines. The presence of free resin-bound thiol groups can also be detected (123). 

Monitor the coupling steps by ninhydrin assay (26) or Bromophenol blue assay (27) in the case of proline to assess the presence of free amines. 

The use of a low excess of the building block requires careful control of the progress of the acylation reaction. Besides the 3-hydroxy-4-oxo-3,4-dihydro-l,2,3-benzotriazine reagent 23, the incorporation of the building block can be monitored by addition of Bromophenol Blue (0.05% of the resin loading) [52,67,73] or Violet Acid 17 [20] to the reaction vessel, as well as the ninhydrin test [74]. If the coupling is carried out by in situ formation of the 1-hydroxybenzotriazole ester, an excess of 1-hydroxyben-zotriazole is required for reliable monitoring with Bromophenol Blue. 

Monitor the migration of the bromophenol blue dye and turn off the power supply when the dye is a few millimeters above the bottom of the gel. 

The addition of just a few grains of bromophenol blue is sufficient. This will provide a dye marker to monitor electrophoresis. 

Free amino functions on the spots can be stained with bromophenol blue (26) prior to the coupling reactions. This allows visual monitoring of the performance of all the synthesis steps. Thus, a standard membrane for SPOT-... 

The absorbance response of pH indicators can be exploited in RET probes since changes in the spectral overlap integral will affect the RET efficiency. A sensor comprised of [Ru(dpp)3] (Fig. 12.3) as the donor, ion-paired with a pH indicator bromophenol blue as the acceptor, and immobilised in a plasticised PVC film, has been developed for the detection of ammonia. In the presence of the analyte, an increase in the deprotonated band of the pH indicator (which overlaps with the emission band of the donor) gives rise to RET, monitored by a decrease in the... 

The completeness of the coupling step can be monitored using the bromophenol blue test. Please note that all traces of DIEA and TMP need to be removed by extensive washing to obtain a reliable result (reeNote 12). 

The formation of the imines and their subsequent reduction was monitored by the disappearance of the starting amine (ninhydrin staining, TLC). Simple quenching with water and drying of the organic solutions with MgS04 constituted the reaction work-up. The condensation of the amines with isothiocyanates and TEA was monitored by TLC (blue bromophenol staining, disappearance of... 

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