Eriochrome cyanine R indicator (C.I. 43820)

Eriochrome cyanine R indicator (C.I. 43820) is a hydroxy triphenylmethane metal complexing dye that forms colored complexes with ferric ions. Eriochrome cyanine R indicator (C.I. 43820) can serve as a nuclear/myelin stain, selectively staining nuclei through an anionic iron-dye complex that binds arginine-rich proteins via weak non-ionic forces, with iron ions rendering nuclei, myelin, and erythrocytes blue. Eriochrome cyanine R indicator (C.I. 43820) can be used as a histological staining reagent alternative to Hematoxylin (HY-N0116) for nuclear and myelin staining; it can also serve as a metal colorimetric indicator for analytical chemistry^[1][2]. In Vitro:Eriochrome cyanine R indicator (C.I. 43820) forms a red solution in concentrated H₂SO₄, a yellow solution with a red precipitate upon dilution, a blue solution in alkaline solution, and an orange-yellow solution in ethanol^[1].
Eriochrome cyanine R indicator (C.I. 43820) exhibits a pH-dependent ultraviolet/visible spectrum, with a peak near 515 nm at pH 4.0 and a peak near 585 nm at pH 12-13^[1].
Eriochrome cyanine R indicator (C.I. 43820) (1.0 g/L; 5 min) produces selective blue nuclear staining in progressive iron staining of hydrated paraffin sections of animal non-neural tissues fixed in neutral buffered 4% formaldehyde^[1].
Eriochrome cyanine R indicator (C.I. 43820) (2.0 g/L; ≥5-20 minutes; 10-second acid-alcohol differentiation) produces selective blue nuclear staining in hydrated paraffin sections of animal tissues fixed in 4% neutral buffered formalin, and produces selective blue staining of myelin sheaths and erythrocytes in hydrated paraffin sections of fixed central nervous tissue, with no nuclear staining^[1].

Eriochrome cyanine R indicator (C.I. 43820) can produce selective blue nuclear staining on paraffin-embedded animal tissue sections and can serve as an alternative to aluminum-hematoxylin staining^[2].