Cotton blue

Name: Cotton blue
Brand: Vaqora Chemicals
SKU: VQ-000542

About Cotton blue

Cotton blue is a biological stain (Microscopy grade) carrying the CAS registry number 28983-56-4. With the molecular formula C37H28N3Na2O9S3+, it has a molar mass of 800.8 g/mol. Alternative names: Methyl Blue and Helvetia Blue.

It is supplied as a dark red brown powder. Keep the container tightly sealed and store it in a cool, dry area. The GHS classification uses the signal word “Warning”, so appropriate gloves, eye protection and ventilation are recommended.

Typical applications include histology and cytology staining, microscopy, clinical laboratories and biological staining. It is used across academic and industrial research, diagnostics and biotechnology and textiles and dyeing.

Available in 25 g, 100 g, 1 kg and 4 x 25 kg packs, Cotton blue is dispatched with a Certificate of Analysis (COA) to destinations worldwide.

Typical applications

Histology & cytology staining
Microscopy
Clinical laboratories
Biological staining

Industries

Specifications & identifiers

Chemical identifiers
Product name	Cotton blue
Catalogue No.	VQ-000542
CAS Number	28983-56-4
IUPAC name	disodium;4-[4-[[4-(4-sulfoanilino)phenyl]-[4-(4-sulfonatophenyl)azaniumylidenecyclohexa-2,5-dien-1-ylidene]methyl]anilino]benzenesulfonate
Molecular formula	C₃₇H₂₈N₃Na₂O₉S₃⁺
Molecular weight	800.8 g/mol
Exact mass	800.0783
Grade	Microscopy
HSN code	32041251
InChIKey	MCPLVIGCWWTHFH-UHFFFAOYSA-M
SMILES	C1=CC(=[NH+]C2=CC=C(C=C2)S(=O)(=O)[O-])C=CC1=C(C3=CC=C(C=C3)NC4=CC=C(C=C4)S(=O)(=O)O)C5=CC=C(C=C5)NC6=CC=C(C=C6)S(=O)(=O)[O-].[Na+].[Na+]
PubChem CID	76956083

Physical properties
Physical form	Powder
Appearance	Dark red brown powder
H-bond donors / acceptors	4 / 11
TPSA	232 Å²
Synonyms	Methyl Blue, Helvetia Blue, Acid Blue 93, C.I. Acid Blue 93, C.I. Acid Blue 93, disodium salt, Ink Blue, Soluble Blue, Helvetia Blue I, Ink Blue Special, Water Blue B, Soluble Blue 8B, Water Blue IN

Safety & hazard information (GHS)

Harmful / irritant

Signal word: Warning

Hazard statements

H302Harmful if swallowed
H315Causes skin irritation
H319Causes serious eye irritation
H335May cause respiratory irritation

Precautionary statements: P261, P305 + P351 + P338

Classification is indicative (aggregated GHS notifications) and may vary by grade and concentration. Always refer to the SDS supplied with your lot.

Documents

Safety Data Sheet (SDS)16-section GHS · on request Certificate of AnalysisTypical / batch COA · on request Specification sheetTDS / MOA · on request

Other grades of CAS 28983-56-4

Aniline blue, water soluble

CAS: 28983-56-4
Formula: C₃₇H₂₈N₃Na₂O₉S₃⁺
MW: 800.8 g/mol

VQ-000471

AR

Aniline blue, water soluble, AR

CAS: 28983-56-4
Formula: C₃₇H₂₈N₃Na₂O₉S₃⁺
MW: 800.8 g/mol

VQ-046703

Microscopy

Methyl blue

CAS: 28983-56-4
Formula: C₃₇H₂₈N₃Na₂O₉S₃⁺
MW: 800.8 g/mol

VQ-000620

Methyl blue, aqueous solution

CAS: 28983-56-4
Formula: C₃₇H₂₈N₃Na₂O₉S₃⁺
MW: 800.8 g/mol

VQ-003592

Frequently asked questions

What is the CAS number of Cotton blue?

The CAS Registry Number of Cotton blue is 28983-56-4. It is also known as Methyl Blue, Helvetia Blue, Acid Blue 93.

What is the molecular formula and molecular weight of Cotton blue?

Cotton blue has the molecular formula C37H28N3Na2O9S3+ and a molecular weight of 800.8 g/mol.

Which grade and pack sizes of Cotton blue can I order?

We supply Cotton blue in Microscopy grade, in 25 g, 100 g, 1 kg, 4 x 25 kg packs. Larger bulk quantities and custom packing are quoted on request.

Do you provide a COA and SDS with Cotton blue?

Yes. Every lot of Cotton blue is shipped with a batch-specific Certificate of Analysis, and a 16-section GHS Safety Data Sheet is provided with the quotation and the shipment.

Can Cotton blue be shipped internationally?

Yes. Cotton blue is classified as hazardous, so it is packed in UN-approved packaging and shipped as dangerous goods under IATA/IMDG rules. We export worldwide on EXW, FOB, CIF and DAP terms.