Can be used to stain cartilage and extracellular matrices blue (it has other uses as well, with different tissue types). The copper present in the dye is responsible for the dye's blue coloration. 

Although the stain is not hazardous, gloves and goggles are strongly recommended, alongside reasonable caution during handling. 

Staining Procedures

Alizarin Red is used to stain calcium (it has other uses as well, with different tissue types). The fact that it stains calcium means that by extension, Alizarin Red stains tissues like bone and cartilage, which contain calcium deposits.

Gloves, goggles, and a mask are advised as PPE when handling this chemical. Do not drink or directly breathe in the compound and do not rinse down drain.

Staining Procedures

Aniline Blue is known for its ability to stain collagen in various trichrome stains. Aniline Blue can also be used to fluorescently stain callose and cellulose in plant cells (read more here). 

Aniline Blue is not hazardous, but it can be a mild irritant if inhaled. Wearing goggles, gloves and a mask is recommended.

Staining Procedures

M. Heidenhain first used the stain in 1915 as a general tissue stain. He saw how it was used by Mallory in Mallory's connective tissue stain (read more here) where he replaced the use of acid fuschin with azocarmine G.  Over the years, the azocarmine modification to Mallory's connective tissue stain became the new standard. 

Azocarmine G is a skin, eye, and respiratory irritant. Although generally not hazardous, protective clothing, gloves, goggles, and a mask are reccomended.

Staining Procedures

Azure A can be used as a subsitute for methyl violet when staining amyloids (a protein that can aggregate in connective tissues). Azure A can also be used to stain mast cells- a type of white blood cell that is found in connective tissue. On a separate note, Azure A can be used to stain mucins (read more here), nuclei (read more here) and as a stain for Diphtheria bacilli (read more here). 

Azure A is a serious eye irritant. Protective goggles are strongly reccomended when handling this stain. Wash your hands after using and make sure to not touch your eyes. If Azure A gets in your eyes, immediately wash your eyes. If irritation persists, seek medical attention. 

Staining Procedures

Bismarck brown was one of the first azo dyes, made by Carl Alexander von Martius (1838-1920) and named after the first chancellor of the German Empire, Otto von Bismarck (chancellor from 1871-1890). Martius went on to become a founding member of the German Chemical Society (1867) as well as the Kaiser-Wilhelm-Institute for Chemistry (1911), which went on to become the modern-day Max Planck Institutes. Bismarck brown is used in plasma stains to color mucin and mast cells. 

Bismarck brown is a serious eye irritant, so take extra care to make sure you wear your lab goggles. Bismarck brown is extremely heat sensitive- so do not boil it. 

Staining Procedures

Fuschin was discovered by Jakub Natanson in 1856 and is derived from coal tar. Fuschin was second ever aniline dye after mauviene, which was discovered by William Henry Perkin that same year. 

Fuschin basic is a suspected carcinogen. Work under a ventilated hood and wear appropriate PPE including goggles, gloves, and a mask.

Staining Procedures

Phosphotungstic Haematoxylin (PTAH) was discovered by Mallory in 1897. Nowadays, there are chemicals that are easier to access that do the same thing as PTAH, but this is a great example of how scientists in the past used more obscure chemicals to accomplish things we now regard as being 'easy'.

PTAH is a skin irritant and a serious eye irritant. Take care to wear goggles, gloves, and protective clothing, potentially adding a face shield.

Staining Procedures

Toluidine Blue O is commonly used as a blue nuclear counterstain (see here), but can also be used for staining mast cells, which are a type of white blood cell found throughout connective tissue. 

Toluidine Blue O itself is not hazardous, but its combustion products, including carbon, nitrogen, and sulfur oxides alongside hydrogen chloride gas, are hazardous. Wear gloves, goggles, protective clothing, and a mask if dust is being generated. 

Staining Procedures