Sudan IV

Sudan IV (C24H20N4O) is a lysochrome (fat-soluble dye) diazo dye used for the staining of lipids, triglycerides and lipoproteins on frozen paraffin sections. It has the appearance of reddish brown crystals with melting point 199 °C and maximum absorption at 520(357) nm. Sudan I, Sudan III, and Sudan IV have been classified as category 3 carcinogen by the International Agency for Research on Cancer. In its purified form it is called Biebrich scarlet R, which should not be confused with the water-soluble Biebrich scarlet.

Sudan IV

Sudan IV (C24H20N4O) is a lysochrome (fat-soluble dye) diazo dye used for the staining of lipids, triglycerides and lipoproteins on frozen paraffin sections. It has the appearance of reddish brown crystals with melting point 199 °C and maximum absorption at 520(357) nm. Sudan I, Sudan III, and Sudan IV have been classified as category 3 carcinogen by the International Agency for Research on Cancer. In its purified form it is called Biebrich scarlet R, which should not be confused with the water-soluble Biebrich scarlet.