- Synonyms: 1-(p-Phenylazophenylazo)-2-naphthol, Sudan red BKr- C22H16N4Or- M = 352,40 g/molr- CAS [85-86-9]r- EINECS-No.: 201-638-4r- Tariff number: 3204 19 00 90r- Applications: microscopy, bacterium staining.rrSPECIFICATIONSrsuitability for microscopy: passes testrr