Direct Red 81
SIAL/195251 - Dye content 50 %
Synonym: DR 81; Disodium 7-
CAS Number: 2610-11-9
Empirical Formula (Hill Notation): C29H19N5Na2O8S2
Molecular Weight: 675.60
EC Number: 220-028-9
MDL Number: MFCD00003949
Linear Formula: C29H19N5Na2O8S2
Product Type: Chemical
| ε (extinction coefficient) | ≥12000 at 272-278 nm in H2O at 0.01 g/L |
| λmax | 397 nm |
| 508 nm (2nd) | |
| application(s) | diagnostic assay manufacturing hematology histology |
| composition | Dye content, 50% |
| form | powder |
| InChI | 1S/C29H21N5O8S2.2Na/c35-2 |
| InChI key | UFUQRRYHIHJMPB-UHFFFAOYSA |
| mp | 240 °C (dec.) (lit.) |
| Quality Level | 100 ![]() |
| SMILES string | [Na+].[Na+].Oc1c(N=Nc2ccc |
| solubility | H2O: 0.1%, dark red |
| storage temp. | room temp |
| technique(s) | microbe id | staining: suitable |
| Biochem/physiol Actions: | Bacterial consortium NBNJ6 has an ability to decolorize direct red 81 (DR81). |
| Packaging: | 25, 100 g in glass bottle |
| RIDADR | NONH for all modes of transport |
| WGK Germany | WGK 3 |
| Flash Point(F) | Not applicable |
| Flash Point(C) | Not applicable |
| mp | 240 °C (dec.) (lit.) |
| Storage Temp. | room temp |
| Colour Index Number | 28160 |
| UNSPSC | 12171500 |

