Connective Tissue Stains

Connective tissues- what are they?

Connective tissues are the structural tissues in our bodies that hold everything together. These include cartilage, bone, ligaments, tendons, and adipose (fat). Below you will find a list of the stains we have in Clapp Laboratory that can stain this type of tissue.

Fawcett, D.W. (2025, February 1). connective tissue. Encyclopedia Britannica. https://www.britannica.com/science/connective-tissue

Kamrani P, Marston G, Arbor TC, et al. Anatomy, Connective Tissue. [Updated 2023 Mar 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538534/

Phosphotungstic Haematoxylin

Khanmohammadi, Manijeh & Khanjani, Sayeh & Bakhtyari, Mahsa & Zarnani, Amir-Hassan & Edalatkhah, Haleh & Akhondi, Mohammad & Mirzadegan, Ebrahim & Kamali, Koorosh & Alimoghadam, Kamran & Kazemnejad, Somaieh. (2012). Proliferation and chondrogenic differentiation potential of menstrual blood- and bone marrow-derived stem cells in two-dimensional culture. International journal of hematology. 95. 484-93. 10.1007/s12185-012-1067-0.

Alcian Blue

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

Note: Alcian blue is a common component of Masson's Trichrome Stain, click here to learn more.

Katti SS, Bhat K, Bogar C. Isolation, Characterization, and Differentiation of Stem Cells From Various Dental Sources: An In Vitro Study. Journal of Advanced Oral Research. 2021;12(2):254-260. doi:10.1177/23202068211010768

Alizarin Red S

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

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

Note: Aniline blue is commonly used in the Gömöri stain and Mallory's trichrome stain. Click here and here to learn more.

Natesan, Shilpa & George, Jose & Krishnapillai, Rekha & P R, Bindhu & Thomas, Priya. (2017). Mast Cell Density in Oral Lesions using Metachromatic Stains: A Comparative Study. Journal of Clinical and Diagnostic Research. 11. ZC17-ZC19. 10.7860/JCDR/2017/30460.10744.

Azure A

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

Tomov, Nikola & Dimitrov, Nikolay. (2017). Modified Bismarck brown staining for demonstration of soft tissue mast cells. Trakia Journal of Sciences, No 3. 15. pp 1 95 - 197. 10.15547/tjs.2017.03.001.

Bismarck Brown Y

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.