Science Meets the Arts: A Short Yet Colorful History of H&E Staining

3 min read

March 25, 2026

Part 1: Hematoxylin

If you have ever stained a slide with hematoxylin and eosin, you may not realize that you are part of a centuries-long line of users stretching back to the Aztec Empire. Today, hematoxylin & eosin - the H and E of H&E staining - are staples in any lab processing tissue samples to view under the microscope.

Stomach tissue stained with H&E

However, these essential dyes made their way into the lab via a fascinating journey from the hulls of Golden Age pirate ships to Van Gogh’s palette.

Mesoamerican Origins

Haematoxylum campechianum, commonly known as the logwood tree or bloodwood tree, is the source of the blue-purple hematoxylin stain. Native to southern Mexico and Central America, the logwood tree’s unique properties were first discovered by the Maya and Aztec peoples who used it to dye clothing and fabrics. When oxidized, hematoxylin is able to produce a range of colors from light gray to deep black. However, hematoxylin’s most prized hue was a rich, vibrant purple.

Raw logwood chips

With the ensuing Spanish colonization, the tree was exported to Europe in the 16th and 17th centuries for use in the textile industries, as purple dyes were both rare and expensive.

Pirates and Privateers

The logwood tree's dye presented merchants with a lucrative profit opportunity and it quickly became a highly sought-after commodity. Haematoxylum dye was a valuable resource in the European textile industry, particularly for royalty and the wealthy, who favored the color purple for its association with nobility and power.

This expensive export became a target for both foreign powers attempting to cash in on the Hematoxylin dye trade, as well as for pirates seeking high-value targets. Just one shipload of logwood could be worth an entire year’s supply of other ship cargo, and soon hundreds of pirate ships were prowling the Caribbean in search of a hematoxylin payload.

The Spanish Empire also had to contend with other European nations as they fought to maintain their monopoly over the logwood trade and would hire privateers to attack enemy ships.

Under the Microscope

One of the first recorded uses of logwood (hematoxylin) in microscopy comes from English Histologist John Quekett in his 1855 book, A Practical Treatise on the Use of the Microscope. He noted that if wood samples were too transparent for examination under a microscope, “they may be dyed with tincture of iodine, or in a decoction of fustic or logwood.”

The use of hematoxylin for tissue staining was popularized eight years later when German anatomist Heinrich Wilhelm Gottfried von Waldeyer-Hartz described his use of ‘Campeche wood’ (another term for logwood) to stain neural axons in 1863. This departure from his usual preferred stain, alkanet, was because he found hematoxylin to be more effective in distinguishing cell nuclei.

Subsequent scientists developed mordants for hematoxylin solution- added chemicals that help the hematoxylin dye bind to unstained material. Mordants improved staining and many of these formulations are still widely used today, named for the researchers who created them: Erhlich, Gill, Mayer, Harris, Verhoef, Weigerts, and more.

Bibliography:

Alvarez-Martin, A., Trashin, S., Cuykx, M., Covaci, A., De Wael, K., & Janssens, K. (2017). Photodegradation mechanisms and kinetics of Eosin-Y in oxic and anoxic conditions. Dyes and Pigments, 145, 376-384. https://doi.org/10.1016/j.dyepig.2017.06.031
Bancroft, J. D., & Layton, C. (2019). The hematoxylins and eosin. In S. K. Suvarna, C. Layton, & J. D. Bancroft (Eds.), Bancroft's Theory and Practice of Histological Techniques (8th ed., pp. 126-138). Elsevier. https://doi.org/10.1016/B978-0-7020-6864-5.00010-4
H01: The haematoxylin and eosin stain: from piracy to pathology. (2021). British Journal of Dermatology, 185(1), 161-161. https://doi.org/10.1111/bjd.20155
Titford, M. (2005). The long history of hematoxylin. Biotechnic & Histochemistry, 80(2), 73–78. doi:10.1080/10520290500138372
Ortiz-Hidalgo, C., & Pina-Oviedo, S. (2018). Hematoxylin: Mesoamerica’s gift to histopathology. Palo de Campeche (logwood tree), pirates’ most desired treasure, and irreplaceable tissue stain. International Journal of Surgical Pathology, 27, 106689691878765. https://doi.org/10.1177/1066896918787652