Eosin B is a form of eosin, which is a chemical compound.

Eosin B (from ancient Greek ἠώς ēōs "dawn"), common name C.I. Acid red 91 is a dye among xanthene dyes and triphenylmethane dyes, which is yellow-red in water and has a weak green fluorescence. [1] Can be used for dyeing of textiles and paper. In addition to eosin B (English bluish "bluish"), eosin Y (English yellowish "yellowish") is also known, which has a wider range of applications than eosin B. Eosin Y has the same basic structure as Eosin B, but the nitro group has been replaced by a bromine atom.

The structure of eosin B is derived from fluorescein, and eosin B can be synthesized by reacting eosin Y with nitric acid[4] Here, two bromine atoms are replaced by nitro groups.

Eosin B can be used for hematoxylin-eosin staining in histology and clinical cytology. In the preparation, cytoplasm, collagen, and elastin stained red with eosin B, while erythrocytes were orange-red. [5] According to another source, the cytoplasm and interstitium are stained orange-red.

Eosin B performs just as well as Eosin Y, sometimes for a more vibrant red.

Eosin is a class of fluorescent red dyes. It is an artificial derivative of fluorescein and consists of two closely related compounds, eosin Y and eosin B. Eosin Y is more commonly used. It is a tetrabromo derivative of fluorescein and is slightly yellow (hence the name eosin yellow). Eosin Y can be further divided into water-soluble and ethanol-soluble Eosin Y. In the author's experience, ethanol-soluble Eosin Y stains faster and more vividly red than water-soluble. Eosin B is a dibromodinitro derivative of fluorescein with a faint blue hue. Eosin B performs just as well as Eosin Y, sometimes for a more vibrant red. These two dyes are interchangeable. Using one or the other may just be a matter of preference or tradition. Eosin can be used to stain cytoplasm, erythrocytes, collagen, and muscle fibers for histological examination. It is most commonly used as a counterstain for hematoxylin in HE staining. In HE, Eosin Y is typically used at a concentration of 0.5–1% (0.5–1 g Eosin Y dissolved in 100 ml distilled water or 75% ethanol).

Yu and Fugetsu [108] developed a novel adsorbent by inserting MWCNTs into the cavities of dolomite for removal of ethidium bromide, acridine orange, methylene blue, eosin B, and eosin Y from wastewater dye. Polyurethane polymers are used as binders to produce foam-wire CNT/dolomite sorbents. Adsorption of cationic dyes, acridine orange, ethidium bromide, and methylene blue reached equilibrium within 30 minutes, while adsorption of anionic dyes, eosin B and eosin Y reached equilibrium within 60 minutes. The maximum adsorption of all studied dyes is reported in Table 3. The foamy ternary composite PUF/diatomaceous earth/dispersed MWNTs showed the highest adsorption capacity for these dyes, followed by PUF/agglomerated MWNTs, and then PUF/dispersed MWCNTs. Langmuir adsorption isotherms are best suited for equilibrium data.