2’3’-cGAM(PS)2 (Rp/Sp)

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2’3’-cGAM(PS)2 (Rp/Sp)

STING ligand

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2 x 250 µg


Bisphosphorothioate analog of 2'3'-cGAMP, (Rp/Sp) cyclic [G(2’,5’)psA(3’,5’)ps]

2’3’-cGAM(PS)2 (Rp/Sp) is composed of Rp,Sp-isomers of the bis-phosphorothioate analog of the mammalian cyclic dinucleotide (CDN) 2’3’-cGAMP [1].

CDNs are microbial messengers that induce innate immune responses in mammals by binding and activating STING (stimulator of interferon genes; also known as ERIS, MITA, MPYS, NET23 and TMEM173) leading to TBK1-IRF3-dependent type I interferon (IFN) production [2, 3].

The most potent natural STING agonist in humans is 2’3’-cGAMP, a CDN produced in mammals by cGAS (cGAMP synthase) in response to double-stranded DNA in the cytoplasm [4, 5].

As STING agonists, 2’3’-cGAMP and other CDNs are being studied for their potential in immunotherapy and vaccination. An obstacle to their therapeutic utility is their lability to enzymatic hydrolysis by various nucleases and phosphodiesterases, some of which are highly specific.

For example, the enzyme ENPP1 (ecto-nucleotide pyrophosphatase/phosphodiesterase) cleaves 2’3’-cGAMP but not other CDNs, such as its bisphosphorothioate analog, 2’3’-cGAM(PS)2.

In fact, this analog is not only more stable than 2’3’-cGAMP but is also more potent [1].



1. Li L. et al., 2014. Hydrolysis of 2'3'-cGAMP by ENPP1 and design of nonhydrolyzable analogs. Nat Chem Biol. 10(12):1043-8.
2. Wu J. et al., 2013. Cyclic GMP-AMP is an endogenous second messenger in innate immune signaling by cytosolic DNA. Science 339(6121):826-30.
3. Sun L. et al., 2013. Cyclic GMP-AMP synthase is a cytosolic DNA sensor that activates the Type I interferon pathway. Science 339(6121):786-91.
4. Gao P. et et al., 2013. Cyclic [G(2',5')pA(3',5')p] is the metazoan second messenger produced by DNA-activated cyclic GMP-AMP synthase. Cell. 153(5):1094-107.
5. Ablasser A. et al., 2013. cGAS produces a 2'-5'-linked cyclic dinucleotide second messenger that activates STING. Nature. 498(7454):380-4.


IRF INDUCTION (Lucia luciferase reporter)
IRF INDUCTION (Lucia luciferase reporter)

THP1-Dual™ cells were stimulated for 24 hours with the STING ligands as shown (all at 10 μg/ml). The interferon regulatory factor (IRF) response was assessed by measuring the activity of Lucia luciferase in the supernatant using QUANTI-Luc™ 4 Lucia/Gaussia. Data are shown in fold response over non-induced cells (mean ± SEM).


THP1-Dual™ cells were stimulated for 24 hours with the STING ligands as shown (all at 10 μg/ml). The NF-κB-induced SEAP activity was assessed using QUANTI‑Blue™ Solution, a SEAP detection reagent. Data are shown as optical density (OD) at 630 nm (mean ± SEM). Non‑induced cells (NI) have been included as a negative control.

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Synonyms: Di-thiophosphate analog of 2’3’cGAMP; c-(RpSp)-ApsGps; 2’3’-cGsAsMP

CAS number: 1637675-05-8 (free acid)

Formula: C20H22N10O11P2S2 •2Na

Molecular weight: 750.5 g/mol

Purity: ≥ 95% by LC/MS & NMR

Solubility: 50 mg/ml in water

Quality control:

  • Purity and structure have been determined by LC/MS and NMR: ≥ 95%.
  • Biological activity has been assessed by measuring the induction of the interferon pathway using cellular assays.
  • The absence of bacterial contamination (lipoproteins & endotoxins) has been confirmed using HEK-Blue™ TLR2 and HEK-Blue™ TLR4 cells.
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  • 2 x 250 µg lyophilized 2’3’-cGAM(PS)2 (Rp/Sp)
  • 1.5 ml endotoxin-free water

Product is shipped at room temperature.

Upon receipt, store at -20°C.

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