1. Product Overview
DAPT (N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester), also known as GSI-IX or γ-Secretase Inhibitor IX (CAS 409345-29-5), is a potent, cell-permeable, and selective peptidomimetic inhibitor of γ-secretase, the intramembrane protease complex responsible for the final cleavage of amyloid precursor protein (APP) and Notch receptors. With the molecular formula C₂₃H₂₆F₂N₂O₄ and a molecular weight of 432.46 g/mol, it appears as a white to off-white solid at room temperature. DAPT inhibits γ-secretase-mediated APP cleavage (IC₅₀ ≈ 20 nM in cell-based Aβ reduction assays) and blocks Notch S3 cleavage (IC₅₀ ≈ 115–150 nM), thereby preventing NICD (Notch intracellular domain) release and subsequent transcriptional activation of Hes/Hey target genes. It is a foundational tool for studying Notch signaling in developmental biology, stem cell differentiation, and amyloid β production in Alzheimer's disease models. This product is supplied exclusively for laboratory research use and is not intended for clinical, diagnostic, veterinary, food, or cosmetic applications.
2. Key Features and Advantages
• Potent γ-secretase inhibition: Reduces Aβ₄₀/Aβ₄₂ secretion in neuronal cultures (IC₅₀ ~20 nM) and inhibits Notch S3 cleavage (IC₅₀ ~115–150 nM); ~100-fold selectivity over α-secretase and other aspartic proteases.
• Well-established Notch pathway probe: Blocks NICD nuclear translocation and Hes1/Hey1 upregulation; widely used to induce neural differentiation of embryonic stem cells (ESCs/iPSCs) by suppressing Notch signaling.
• Cell-permeable & stable: Readily enters cells; DMSO stocks are stable at -80°C for >6 months; activity confirmed across multiple cell lines (HEK293, Neuro-2a, C2C12, hESCs).
• High purity: Typically ≥98% by HPLC (suppliers offer 98–99%+), suitable for Western blot (NICD, Hes1, CTFγ/APP intracellular domain), qPCR (Hes/Hey targets), and immunofluorescence.
• Good solubility: Soluble in DMSO (≥10 mg/mL = ~23 mM; prepare 5–10 mM stock in anhydrous DMSO), also soluble in ethanol; practically insoluble in water. Light-sensitive — protect from prolonged light exposure.
• Consistently referenced: Cited in >2,000 publications since 2000 for Notch biology, stem cell fate mapping, AD amyloid processing, and cancer stem cell studies.
3. Main Applications
• Notch signaling research: Evaluating γ-secretase inhibition on Notch1–4 S3 cleavage, NICD accumulation, and Hes/Hey target gene expression in fibroblasts, endothelial cells, and cancer lines.
• Stem cell differentiation: Promoting neurogenesis from ESCs/iPSCs, NSCs by transient DAPT treatment to suppress Notch; also used in mesenchymal-to-epithelial transition (MET) and pancreatic/endothelial differentiation protocols.
• Alzheimer's disease models: Measuring effect on Aβ₄₀/Aβ₄₂ ratio, sAPPα/sAPPβ levels, and testing γ-secretase modulator vs inhibitor phenotypes in neuronal cultures and APP transgenic mice.
• Cancer stem cell studies: Assessing Notch-dependent CSC populations in breast, colon, glioblastoma; combinatorial with chemotherapy to test CSC eradication.
• Developmental biology: In vivo zebrafish/xenopus assays for somitogenesis, neurogenesis, and vascular development where Notch inhibition phenocopies genetic knockouts.
4. Technical Specifications
5. Storage and Handling
• Store the powdered compound sealed with desiccant, protected from light (amber vial or foil-wrapped); recommended storage at -20°C (long term 2–3 years) or 4°C (≤6 months). For DMSO stock solutions, aliquot and store at -80°C wrapped in foil (6–12 months stable) or -20°C (1–2 months); avoid repeated freeze–thaw cycles. Typical working stocks are 5 mM or 10 mM in anhydrous DMSO, stored in amber tubes.
• Before opening, allow the sealed vial to warm to room temperature to prevent moisture condensation. Keep container tightly closed and wrapped in aluminum foil when not in use.
• Handle in a well-ventilated area or fume hood. Use personal protective equipment including safety glasses, nitrile gloves, and a lab coat. Avoid inhalation of dust and contact with skin or eyes.
• Intended exclusively for laboratory research by qualified personnel; not for human or veterinary use, food, drug, or cosmetic applications.
6. Safety Overview
• DAPT is a research chemical γ-secretase inhibitor with significant biological activity at low nanomolar concentrations. Treat as potentially hazardous: may cause irritation to eyes, skin, and respiratory system.
• In case of eye contact, rinse immediately with plenty of running water for at least 15 minutes and seek medical advice. In case of skin contact, wash thoroughly with soap and water.
• If inhaled, move the person to fresh air and keep at rest in a position comfortable for breathing. If ingested, rinse mouth and seek medical attention—do not induce vomiting unless directed by medical personnel.
• Use appropriate engineering controls (fume hood) and personal protective equipment (safety goggles, nitrile gloves, lab coat). Avoid generating dust.
• Dispose of in accordance with local regulations for chemical waste. Do not discharge into drains, waterways, or soil.
• For detailed safety information, refer to the applicable Safety Data Sheet (SDS) prior to handling.
