Skip to content
Molekula

Molekula

Acid Red 388 (Rhodamine WT)

SKU 42776804 CAS 37299-86-8 C29H29N2O5•Cl•Na2 MW 566.98 Made to order 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, also called Rhodamine WT, is a fluorescent dye used mainly as a water tracer in hydrology, including groundwater and surface-water flow studies and dye-dilution measurements. It emits bright orange fluorescence under green excitation, making it ideal for sensitive detection applications. This chemical has a CAS number of 37299-86-8, with the molecular formula C29H29N2O5•Cl•Na2 and a molecular weight of 566.98. It is stable at ambient storage conditions but requires careful handling, as indicated by its "Warning" signal word. Molekula supplies Acid Red 388 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 — $58.80 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 Red solid
Identification (IR) Conforms to Reference
UV/VIS 0.436%

Storage & handling

Property Value
Storage Temperature Ambient
Acidity Base

Literature values

Published physical properties of the substance, not batch specifications.

Property Value
Appearance Dark powder
pKa pKa = 5.1
log P (octanol/water) -1.33

Source: PubChem CID 37718 (HSDB)

Identification

Property Value
SKU 42776804
CAS Number 37299-86-8
IUPAC Name disodium;4-[3-(diethylamino)-6-diethylazaniumylidenexanthen-9-yl]benzene-1,3-dicarboxylate;chloride
Molecular Formula C29H29N2O5•Cl•Na2
Molecular Weight 566.98
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
HTS Code 3204125090
Tariff Code 3204120090

Safety & GHS

Warning
  • GHS pictogram — Health Hazard Health Hazard GHS07

Hazard statements

  • H315 Causes skin irritation
  • H319 Causes serious eye irritation

Precautionary statements

  • P280 Wear protective gloves/protective clothing/eye protection/face protection
  • P301+312 IF SWALLOWED: Call a POISON CENTER or doctor/physician if you feel unwell
  • P302+352 IF ON SKIN: Wash with soap and water
  • P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing

Documents

Safety Data Sheets (SDS)

Available in English, French, German, Italian, Spanish.

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

No alternate names recorded for this product.

Frequently asked questions

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

Acid Red 388 (Rhodamine WT) is primarily used as a fluorescent water-tracing dye in hydrological and environmental studies, such as groundwater and surface-water flow tracing and dye-dilution studies.

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

The chemical formula is C₂₉H₂₉N₂O₅•Cl•Na₂ with a molecular weight of 566.98 g/mol.

How should Acid Red 388 be stored?

Store at ambient temperature in a tightly sealed container, away from moisture and direct sunlight.

What grade or purity is Acid Red 388 available in?

Molekula supplies Acid Red 388 in analytical and technical grades, with purity typically ≥95% unless specified otherwise.

Can Molekula supply Acid Red 388 in bulk quantities?

Yes, we offer bulk quantities of Acid Red 388 upon request, subject to availability and order minimums.

What documentation comes with an order of Acid Red 388?

Each order includes a Certificate of Analysis (CoA), Material Safety Data Sheet (MSDS), and a product specification sheet.

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