Trypan Blue works as a vital stain that finds application in selectively coloring dead tissues. As a diazo dye, it may also be used in trypan blue based cytotoxitiy as well as proliferation assays and is not absorbed by healthy viable cells. It enters cells that are damaged or dead and mark them in blue color, thus allowing them to be counted.

Features :

• Can enter dead cells that allows for their counting
• As live cells are excluded from staining, the process is also called dye exclusion method
• Also known as diamine blue and niagara blue
• Commonly used in microscopy for cell counting process
• Can be used for observing fungal hyphae and stramenopiles

Orange G is valuable acid dye that finds application in many staining processes. Further, it can be combined with other yellow dyes using alcoholic solution for staining erythrocytes in trichrome method where it demonstrates cells in pituitary and pancreas.

Features :

• As synthetic AZO dye it is used in histology in staining formulations
• Normally available as disodium salt
• Having appearance of orange crystals/powder
• Main usage is in OG-6 papanicolaou stain
• Also used as main component for pollen staining in Alexander test
• Can be combined with other yellow dyes for staining erythrocytes in trichrome method
• Suitable for use as color marker for monitoring process of 1% agarose gel electrophoresis

Methylene Blue works as a general biological stain that finds usage for highlighting parts of bacteria, animal as well as blood tissue specimens and works by staining acidic cell parts blue. Also having application in biology & chemistry fields, it is available in solid, odorless and dark green powder form in room temperatures and yields blue solution on event of being dissolved in water.

Features :

• Works as potent cationic dye that has maximum absorption of light
• Comprise dark green crystals/crystalline powder with bronze-like luster
• When mixed in water/alcohol it provides deep blue color

Applications :

• Used as bacteriologic stain and as indicator
• Used as stain in bacteriology and as oxidation-reduction indicator
• Use in endoscopic polypectomy as adjunct to saline/and is injected into sub mucosa around body growth that needs to be removed
• Also used as dye in chromo endoscopy where it is sprayed on mucosa of gastrointestinal tract for identification of dysplasia
• Used in staining for making nuclei more observable
• Also used in staining blood film and in cytology