There are three isomers of toluidine, which are organic compounds. These isomers are o-toluidine, m-toluidine, and p-toluidine, with the prefixed letter abbreviating, respectively, ortho; meta; and para. All three are aryl amines whose chemical structures are similar to aniline except that a methyl group is substituted onto the benzene ring. The difference between these three isomers is the position where the methyl group (–CH3) is bonded to the ring relative to the amino functional group (–NH2). Read more here.
O-toluidine appears as a clear colorless or light yellow liquid. May become reddish brown on exposure to air and light. Flash point 185°F. Has about the same density as water and is very slightly soluble in water. Vapors are heavier than air. Confirmed carcinogen. O-toluidine is an aminotoluene in which the amino substituent is ortho to the methyl group. It has a role as a carcinogenic agent. The chemical properties of the toluidines are quite similar to those of aniline and toluidines have properties in common with other aromatic amines. Due to the amino group bonded to the aromatic ring, the toluidines are weakly basic. None of the toluidines is very soluble in pure water, but will become soluble if the aqueous solution is acidic due to formation of ammonium salts, as usual for organic amines. At room temperature and pressure, ortho- and meta-toluidines are viscous liquids, but para-toluidine is a flaky solid. This can be explained by the fact that the p-toluidine molecules are more symmetrical and fit into a crystalline structure more easily. p-Toluidine can be obtained from reduction of p-nitrotoluene. p-Toluidine reacts with formaldehyde to form Troger's base. Read more here.
Toluidine blue is a basic thiazine metachromatic dye with high affinity for acidic tissue components, thereby staining tissues rich in DNA and RNA. It has found wide applications both as vital staining in living tissues and as a special stain owing to its metachromatic property.Read more here.
Information About Toluidine Blue Stain From Wikipedia
Toluidine blue is a basic thiazine metachromatic dye with high affinity for acidic tissue components. It stains nucleic acids blue and polysaccharides purple and also increases the sharpness of histology slide images. It is especially useful today for staining chromosomes in plant or animal tissues, as a replacement for Aceto-orcein stain. It is used in forensic examination, renal pathology and neuropathology.Read more here.
Several dyes are used extensively in ophthalmic surgery. Toluidine blue (ToB) is an acidophilic metachromatic dye that stains abnormal tissue dark royal blue by penetrating into the nuclei of cancerous cells where it has a selective affinity for nucleic acids and by accumulating in the intercellular spaces.Read more here.
Toluidine blue is a basic thiazine metachromatic dye with high affinity for acidic tissue components, thereby staining tissues rich in DNA and RNA. Use of toluidine blue in tissue sections is done with the aim to highlight components, such as mast cells granules, mucins, and cartilage.Read more here.
The use of the stain toluidine blue provides a colour difference between lignified and non-lignified cell walls, clearly highlighting specialised cells and one adaptation they have. This experiment provides a quick and eye-catching way to teach about the vascular tissue in plants and the structure of plant stems.Read more here.
It is an eye irritant. Its toxicity has not been quantified but has proven to be highly toxic to laboratory animals when injected intravenously. Other dyes in this group are known to be highly toxic, e.g. methylene blue.Read more here.
Toluidine blue is an important tool to detect and document genital and perianal injuries following sexual assault. Application of toluidine blue dye and its subsequent removal from unstained areas by means of a destaining reagent, such as diluted acetic acid or a lubricant has been shown to increase the detection rate of posterior fourchette lacerations from 16% to 40% in adult rape victims. Currently, limited information on toluidine blue positive findings in sexually active control groups imposes some limitation on the interpretation of these injuries.Read more here.
The strongly acidic macromolecular carbohydrates of mast cells and cartilage are coloured red by the blue dye, a phenomenon called metachromasia. Alkaline solutions of toluidine blue are commonly used for staining semi-thin (0.5 to 1 μm) sections of resin-embedded tissue.Read more here.
Toluidine blue is a cationic metachromatic dye that may selectively bind to free anionic groups such as sulfate, phosphate, and carboxylate radicals of large molecules (6). It has been used for decades as an aid to the identification of mucosal abnormalities of the cervix as well as in the oral cavity.Read more here.
Early diagnosis of squamous cell carcinoma on mucosal surfaces can be lifesaving, and examination of mucosal sites should be included in the general dermatologie examination. Difficulty in distinguishing the erythematous lesions appropriate for biopsy and treatment can be partially overcome with the use of a supravital stain well known to oral surgeons. This paper recommends the addition of this test to the dermatologist's armamentarium. Five patients with mucosal in situ squamous cell carcinoma were treated. Three had squamous cell carcinoma of the glans penis, one of the vulva, and one of the oral mucosa. In all patients the toluidine blue test was helpful in the diagnosis of subclinical malignant epithelium, in the delineation of the lesion borders as a guide for surgery, and, postoperatively, in the detection of early disease recurrence. The toluidine blue test, which is a simple procedure accessible to all dermatologists, can help achieve early diagnosis and effective treatment of mucosal squamous cell carcinoma.Read more here.
There is a pressing need for the development of visual aids that will facilitate the detection of oral premalignant lesions (OPLs) with a high-risk of progression. Preliminary data suggest that toluidine blue stain may be preferentially retained by OPLs with high-risk molecular clones. In this study, we monitored OPLs from 100 patients without any history of oral cancer for an average of 44 months in order to evaluate the association of toluidine blue status with clinicopathologic risk factors, molecular patterns (microsatellite analysis on seven chromosome arms: 3p, 9p, 4q, 8p, 11q, 13q, and 17p) and outcome. Toluidine blue–positive staining correlated with clinicopathologic risk factors and high-risk molecular risk patterns. Significantly, a >6-fold elevation in cancer risk was observed for toluidine blue–positive lesions, with positive retention of the dye present in 12 of the 15 lesions that later progressed to cancer (P = 0.0008). This association of toluidine blue status with risk factors and outcome was evident even when the analysis was restricted to OPLs with low-grade or no dysplasia. Our results suggest the potential use of toluidine blue in identifying high-risk OPLs.Read more here.