Toluidine blue, reduction

Various solutions have been proposed for the reduction or elimination of autofluorescence. One way is to chemically suppress the autofluorescence signal with some reagents such as sodium borohydride, glycine or toluidine blue. However, in many cases, these approaches are either infeasible or ineffective, and none of them fully eliminates the problem. The second way is to use spectral unmixing algorithms subtracting the background fluorescence. This is only possible if you have at your disposal complicated, expensive confocal optics with sophisticated automated software (http //www.cri-inc.com/applications/fluorescence-microscopy.asp). 

Kinetics of Reduction of Toluidine Blue with Sulfite - Kinetic Salt Effect in Elucidation of Mechanism 244... 

Presumably because of the relatively high content of phenolic amino acids, products based on milk are strongly autofluorescent when viewed after either 360 nm or 490 nm wavelength excitation. Methods for fluorescence reduction such as prior staining with Toluidine Blue O or Evan s Blue can be employed, especially on sectioned material where artifactual collapse of the emulsion which is caused by the charged nature of the dye, is not an issue [22],... 

A number of methods for determining Mo have been based on its catalytic effect in oxidation of iodide by hydrogen peroxide [112-118], or in reduction of some organic substances, e.g. Nile Blue [119], Toluidine Blue [120], Metanilic Yellow [121], Safranine [122], and Nile Red [123] by suitable reducing agents. 

Kiese M, Lorcher W, Weger N, et al. 1972. Comparative studies on the effects of toluidine blue and methylene blue on the reduction of ferrihaemoglobin in man and dog. Europ J Clin Pharmacol 4 115-118. 

S. B. Jonnalagadda and N. R. Gollapalli [/. Chem. Educ., 77 506 (2000)] studied the effect of ionic strength on the kinetics of the reduction of toluidine blue (TB" ) with sulfite ions in aqueous solution. The stoichiometry is... 

The reduction of toluidine blue by 8204 in HCI-H2O has a 1.39 order in dithionite ion. The reaction rate increases with increase in H+. The rate is affected by the ionic strength and dielectric constant of the medium and addition of 804 and N03 retard the rate. ... 

The major reaction in the reduction of toluidine blue (TB+) by phenylhydrazine (Pz) is °... 

IDO is known to require the presence of cofactors not only to initiate but also to maintain the apparent maximal catalytic activity [206, 207]. IDO requires superoxide anion (O2 0 or a reductant such as ascorbic acid and cofactors such as methylene blue or toluidine blue [165, 196], tetrahydrobiopterin, and dihydroriboflavin mononucleotide (FMNH2) [208-210]. The presence of a site for these cofactors in IDO is likely. 

Other chemiluminescence FIA methodologies for AA determination are based on AA acidic reduction of potassium dichromate to generate Cr(III) and subsequent luminol-hydrogen peroxide-Cr(III) chemiluminescence reaction [87,88], and on chemiluminescence reaction of AA with potassium permanganate in the presence of formaldehyde [89,90], formic acid [91], or CdTe nanocrystals [92] as sensitivity enhancers. Quinine is also used as an enhancer of chemiluminescence produced by reaction between AA and Ce(IV) in acid media [93]. Perez-Ruiz et al. [94] proposed a chemiluminescent reaction, in alkaline solution, of lucigenin with the products from the photooxidation of AA sensitized by toluidine blue. 

Full shades of Toluidine Red are extremely lightfast and weatherfast, but deteriorate rapidly as the pigment is reduced with white pigment. In full shades, the lightfastness equals step 7 on the Blue Scale, while 1 4 Ti02 reductions only reach step 4. The pigment is therefore used preferably in full or similarly deep shades. Recommendations include emulsion paints for interior application or short-term advertisement and marking purposes. 

If they are ingested, dyes and particularly those that have an azo group can be metabolized by the intestinal microflora or by the liver enzymes. So, their effects can occur in organs responsible for metabolism or elimination, like the liver and urinary tract. Skin metabolism may also be responsible for the transformation of dyes, for example, those from colored textiles that can leach from the fabric and migrate to the skin. For example Disperse Orange 3 is degraded to p-phenylenediamine (PPD) and nitro-aniline in the skin (Figure 1). Direct Blue 14 (Cl 23850), after azo reduction, converts to the aromatic amine o-toluidine and other amines when incubated with cultures of Staphylococcus aureus. 

Agar overlay with tetrazolium salt a-Naphthol plus dimethylpapraphenylenediamine a-Naphthylbutyrate plus diazo salt of fast blue RR Reduction of nitro blue tetrazolium salt Sodium a-naphthyl acid phosphate plus diazo salt of 5-chloro-o-toluidine... 

---