R2625 Sigma-Aldrich

Retinoic acid

≥98% (HPLC), powder

Synonym: ATRA, Tretinoin, Vitamin A acid, all-trans-Retinoic acid

  • CAS Number 302-79-4

  • Empirical Formula (Hill Notation) C20H28O2

  • Molecular Weight 300.44

  •  Beilstein/REAXYS Number 2057223

  •  EC Number 206-129-0

  •  MDL number MFCD00001551

  •  PubChem Substance ID 24278674

  •  NACRES NA.77



Related Categories Antitumor Agents, Bioactive Small Molecule Alphabetical Index, Bioactive Small Molecules, Bioactives and Supplements for Stem Cell Expansion, Bioactives/Supplements,
Quality Level   200
biological source   synthetic (organic)
assay   ≥98% (HPLC)
form   powder
application(s)   cell culture | mammalian: suitable
color   yellow
mp   180-181 °C (lit.)
storage temp.   −20°C
SMILES string   CC1=C(\C=C\C(C)=C\C=C\C(C)=C\C(O)=O)C(C)(C)CCC1
InChI   1S/C20H28O2/c1-15(8-6-9-16(2)14-19(21)22)11-12-18-17(3)10-7-13-20(18,4)5/h6,8-9,11-12,14H,7,10,13H2,1-5H3,(H,21,22)/b9-6+,12-11+,15-8+,16-14+
Gene Information   human ... RARA(5914), RARB(5915), RARG(5916), RXRA(6256), RXRB(6257), RXRG(6258)
mouse ... Rara(19401), Rarb(218772), Rarg(19411), Rxrb(20182)



• Retinoic acid (RA) has been used for the differentiation of embryonic stem cells into motor neurons.
• It has been used for the differentiation of Xenopus ectoderm into pancreas.
• It has also been used to study epigenetic regulation by RARα (retinoic acid receptor α).
• It has been used to study RA signaling of prospermatogonia transition into spermatogonia.


1, 5 g in ampule

50, 100, 500 mg in ampule

Biochem/physiol Actions

all−trans−Retinoic acid (ATRA) is a ligand for both the retinoic acid receptor (RAR) and the retinoid X receptor (RXR). The bound RAR and RXR act as transcription factors that regulate the growth and differentiation of both normal and malignant cells. Cytochromes P450 (CYPs) catalyze the 4-hydroxylation of ATRA. Retinoic acid primes embryonic stem cells to become neurons.

Features and Benefits

This compound is also offered as part of Sigma′s Library of Pharmacologically Active Compounds (LOPAC®1280), a biologically annotated collection of high-quality, ready-to-screen compounds. Click here to learn more.

This compound is featured on the Nuclear Receptors (Non-Steroids) page of the Handbook of Receptor Classification and Signal Transduction. To browse other handbook pages, click here.

Other Notes

Tandem Mass Spectrometry data independently generated by Scripps Center for Metabolomics is available to view or download in PDF. R2625.pdf Tested metabolites are featured on Scripps Center for Metabolomics METLIN Metabolite Database. To learn more, visit

Legal Information

LOPAC is a registered trademark of Sigma-Aldrich Co. LLC

Safety & Documentation

Safety Information

GHS07  GHS07
Signal word 
Hazard statements 
Personal Protective Equipment 
UN 3077 9 / PGIII
WGK Germany 
Flash Point(F) 
Not applicable
Flash Point(C) 
Not applicable


Certificate of Analysis (COA)

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Certificate of Origin (COO)

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Frequently Asked Questions

What are the I.U. for Product R2625, Retinoic acid?
This product is not characterized by the activity in I.U. The purity specification, however, is not less than 98% by HPLC.
What is Product R2625, Retinoic acid soluble in?
Retinoic Acid is soluble in DMSO at about 40 mg/ml.
How should I store the solutions of Product R2625, Retinoic acid?
Retinoic acid is sensitive to air and light. Solutions should be stored under argon gas, preferably as aliquots at -70°C.
What is the shelf life of Product R2625, Retinoic acid?
R2625 has a shelf-life of two years. Shelf-life dates are found on Specification sheet on our website.
Why is Product R2625, Retinoic acid not shipped on dry ice?
Dry ice is not necessary for shipment, since Product No. R2625 is stable to ship at ambient temperature for up to two weeks. Once received, it should be stored at -20°C.
Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.
How do I get lot-specific information or a Certificate of Analysis?
The lot specific COA document can be found by entering the lot number above under the "Documents" section.
How do I find price and availability?
There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote. USA customers: 1-800-325-3010 or view local office numbers.
What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product.
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Protocols & Articles


Derivation of Functional Oligodendrocyte Progenitor Cells (OPCs) from Human Neural Stem Cell Lines

Introduction Methods    Human Neural Stem Cell Culture    Oligodendrocyte Differentiation and Maturation    Oligodendrocyte Progenitor Cell Characterization    In Vitro Myelination Assay Results Conc...
Christine Chen, Michael Moeller, Anna Abai, Nick Asbrock and Vi Chu1
MilliporeSigma, Bioscience Division, Temecula, CA, USA
Keywords: Adhesion, Atomic absorption spectroscopy, Cell culture, Cell proliferation, Central Nervous System, Clinical, Culture media, Diseases, Gene expression, Growth factors, Hormones, Neurodegenerative Diseases, Pharmaceutical, Phase transitions, RNA immunoprecipitation, Transfection

MSMLS Online Plate Map

Metabolite descriptors included with the software download upon purchase of the product include: Name, Parent CID, molecular formula, molecular weight, CAS, ChEBI, HMDB ID, PubChem Compound and Subst...
Keywords: Mass spectrometry, Metabolites

Retinoic Acid and Gene Expression

All-trans retinoic acid (RA, ATRA) is a pleiotropic activation factor that regulates genes associated with normal vertebrate cellular processes such as cell differentiation, cell proliferation, apopt...
BioFiles 2008, 3.9, 12.
Keywords: Apoptosis, Cancer, Cell proliferation, Cellular processes, Chromatin immunoprecipitation, Condensations, Degradations, Diseases, Gene expression, Hormones, Immunoprecipitation, Ligands, Metabolism, Oxidations, Phosphorylations, Polymerase chain reaction, Sequences, Teratogens, Transcription, Type, Ubiquitinations, Usage, Vitamins


Neural Stem Cell Culture Protocols

Introduction Methods     Isolation of Neural Stem Cells         Isolation of NSCs from Neural Tissue         Differentiation of Human iPSCs into NSCs         Characterization of Neural Stem Cells    ...
Keywords: AGE, Adhesion, Apoptosis, Cell culture, Central Nervous System, Cryopreservation, Culture media, Diseases, Growth factors, High performance liquid chromatography, Phase transitions, Phosphorylations, Purification

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