Skip to content
Molekula

Molekula

Acid Red 388 liquid (Rhodamine WT 20% aqueous solution)

SKU 90028160 CAS 37299-86-8 C29H29ClN2Na2O5 MW 566.99 In stock Bulk quantities on request

Supplying 4,500+ customers in over 80 countries

ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need

Acid Red 388 liquid, also known as Rhodamine WT, is a water-soluble fluorescent dye primarily used in textile dyeing, paper manufacturing, and as a tracer in environmental studies. This 20% aqueous solution features a CAS number of 37299-86-8, with the molecular formula C29H29ClN2Na2O5 and a molecular weight of 566.99. It requires ambient storage conditions and carries no signal word for hazard classification. Molekula supplies Acid Red 388 liquid from research to bulk quantities with full documentation and ISO 9001:2015 traceability.

Expect a response within hours Speak to a chemist: +44 (0) 3302 000333

Example image for illustration only. Other packaging and pack sizes are available.

Pricing & pack sizes

Pack sizes & pricing

These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.

Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.

  • 25 mL — $58.70 per pack

Need a different quantity or pack?

Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.

Quantity
Unit
Needed by
Full name
Email
Company
Phone (optional)
Notes

Expect a response within hours

Prices exclude VAT/sales tax and shipping.

Specifications

Property Value
Appearance Dark red liquid
pH >10.00
Assay 19.37 - 23.03%
Colour Strength 2.08 - 2.47 mg/100ml
Absorbance 0.405 - 0.482 Abs

Storage & handling

Property Value
Storage Temperature Ambient
Acidity Acid

Identification

Property Value
SKU 90028160
CAS Number 37299-86-8
IUPAC Name disodium;4-[3-(diethylamino)-6-diethylazaniumylidenexanthen-9-yl]benzene-1,3-dicarboxylate;chloride
Molecular Formula C29H29ClN2Na2O5
Molecular Weight 566.99
Exact Mass 566.156
SMILES CCN(CC)C1=CC2=C(C=C1)C(=C3C=CC(=[N+](CC)CC)C=C3O2)C4=C(C=C(C=C4)C(=O)[O-])C(=O)[O-].[Na+].[Na+].[Cl-]
InChIKey NRZDMKVYRRMFRR-UHFFFAOYSA-L
InChI InChI=1S/C29H30N2O5.ClH.2Na/c1-5-30(6-2)19-10-13-22-25(16-19)36-26-17-20(31(7-3)8-4)11-14-23(26)27(22)21-12-9-18(28(32)33)15-24(21)29(34)35;;;/h9-17H,5-8H2,1-4H3,(H-,32,33,34,35);1H;;/q;;2*+1/p-2
PubChem CID 37718
REACH Code Y110
Tariff Code 32129000

Safety & GHS

Detailed safety information available in the SDS — see Documents below.

Documents

Certificate of Analysis (CoA) by batch

Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.

Synonyms

  • Acid Red 388
  • C29H29ClN2Na2O5
  • NRZDMKVYRRMFRR-UHFFFAOYSA-L
  • RHODAMINE WT
  • Sodium 4-(3,6-bis(diethylamino)xanthylium-9-yl)isophthalate chloride

Frequently asked questions

What is Acid Red 388 (Rhodamine WT) used for?

Acid Red 388 (Rhodamine WT) is a fluorescent water-tracing dye, used mainly as a hydrological and environmental tracer in flow, dispersion and dye-dilution studies.

What is the chemical formula and molecular weight of Acid Red 388?

The chemical formula is **C₂₉H₂₉ClN₂Na₂O₅**, and the molecular weight is **566.99 g/mol**.

How should Acid Red 388 be stored?

Store at **ambient temperature** in a tightly sealed container, protected from prolonged light exposure.

What grade or purity is available for Acid Red 388?

Molekula supplies Acid Red 388 as a **20% aqueous solution** with analytical-grade purity suitable for research applications.

Can Molekula supply Acid Red 388 in bulk quantities?

Yes, bulk quantities are available upon request—contact our sales team for custom packaging and pricing.

What documentation comes with an order of Acid Red 388?

Each order includes a **Certificate of Analysis (CoA)**, Material Safety Data Sheet (MSDS), and batch-specific documentation.

Ready to order or need a custom pack?

Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.

Talk to a chemist
Documents Pricing
Request a quote
Tell us the product and the quantity you need — including quantities larger than our listed packs. Expect a response within hours.
Full name
Company
Email
Phone (optional)
Product
Quantity needed

Ask for whatever you actually need — the pack sizes on our catalogue pages are a starting point, not a limit.

Message
View basket