SS-31 FAQ for Laboratory Researchers
This technical guide and SS-31 FAQ provides laboratory researchers with analytical data, handling parameters, and preclinical mechanism overviews for SS-31 (Elamipretide). Developed strictly for in vitro and laboratory research, this resource addresses molecular specifications, purity verification, and assay design considerations.
Quick answer
This technical guide and SS-31 FAQ provides laboratory researchers with analytical data, handling parameters, and preclinical mechanism overviews for SS-31 (Elamipretide). Developed strictly for in vitro and laboratory research, this resource addresses molecular specifications, purity verification, and assay design considerations.
Key takeaways
- [SS-31](/research-peptides/ss-31), also known in scientific literature as Elamipretide or Szeto-Schiller 31, is a synthetic tetrapeptide designed to selectively target the inner mitochondrial membrane (IMM).
- The primary biochemical target of [SS-31](/research-peptides/ss-31) is cardiolipin, a unique phospholipid located almost exclusively within the inner mitochondrial membrane.
- To ensure precise reproducible data in cell culture and tissue homogenate assays, research reagents must adhere to rigorous analytical standards.
- When evaluating small-molecule and peptide regulators of mitochondrial function, laboratory investigators frequently compare [SS-31](/research-peptides/ss-31) against mitochondrial-derived peptides (MDPs) such as [MOTS-c](/product/mots-c) and [Humanin](/product/humanin).
Introduction to SS-31 (Elamipretide) in Mitochondrial Research
SS-31, also known in scientific literature as Elamipretide or Szeto-Schiller 31, is a synthetic tetrapeptide designed to selectively target the inner mitochondrial membrane (IMM). Structurally defined as D-Arg-Dmt-Lys-Phe-NH2 (where Dmt represents 2',6'-dimethyltyrosine), SS-31 possesses an alternating aromatic-cationic motif that facilitates cell permeability and specific localization to cardiolipin-rich membrane microdomains without relying on mitochondrial membrane potential.
In preclinical model systems, SS-31 has emerged as a cornerstone compound for investigating cellular bioenergetics, electron transport chain efficiency, and reactive oxygen species (ROS) mitigation. Investigators utilizing our high-purity SS-31 peptide focus primarily on its ability to stabilize cardiolipin structure, thereby optimizing ATP production and preventing cytochrome c release during oxidative stress assays. All research conducted with SS-31 must remain strictly confined to non-human in vitro and preclinical experimental setups.
Molecular Mechanism and Cardiolipin Binding Properties
The primary biochemical target of SS-31 is cardiolipin, a unique phospholipid located almost exclusively within the inner mitochondrial membrane. Cardiolipin plays a critical structural role in organizing respiratory chain complexes (I through IV) into functional supercomplexes (respirasomes) required for efficient oxidative phosphorylation. During pathological states or oxidative stress, cardiolipin undergoes peroxidation, destabilizing electron transport complexes and promoting mitochondrial permeability transition pore (mPTP) opening.
Preclinical data indicate that SS-31 electrostatic interactions allow it to insert into cardiolipin headgroups, effectively shielding cardiolipin from oxidative damage and preserving cristae architecture. Research models exploring cellular energy pathways frequently reference our mitochondrial peptides research hub to compare how cardiolipin stabilization influences overall cellular respiration parameters in isolated organelles and cell lines.
Analytical Standards: HPLC, Mass Spectrometry, and Endotoxin Control
To ensure precise reproducible data in cell culture and tissue homogenate assays, research reagents must adhere to rigorous analytical standards. PX1 Research synthesizes all compounds in domestic, GMP-compliant facilities and verifies lot identity and purity using High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS). Each batch of SS-31 is guaranteed to meet or exceed 98.0% purity as determined by peak area integration.
Because mitochondrial assays—particularly those measuring oxygen consumption rate (OCR) or inflammatory signaling in immune cell lines—are highly sensitive to bacterial contaminants, endotoxin testing is essential. PX1 subjects every lot to Chromogenic LAL testing in an ISO 17025 accredited laboratory, certifying endotoxin levels below 0.01 EU/mg. For a broader overview of quality control metrics across our catalog, review our technical guide on endotoxin testing standards in peptides.
Comparative Analysis: SS-31 vs. MOTS-c vs. Humanin
When evaluating small-molecule and peptide regulators of mitochondrial function, laboratory investigators frequently compare SS-31 against mitochondrial-derived peptides (MDPs) such as MOTS-c and Humanin. While all three compounds influence bioenergetic signaling, their primary mechanisms of action and molecular targets differ substantially.
SS-31 acts directly as a structural stabilizer at the inner mitochondrial membrane by binding cardiolipin, exerting physical protection over respirasome supercomplexes. In contrast, MOTS-c functions predominantly as a nuclear-translocating metabolic regulator involved in glucose homeostasis and AMP-activated protein kinase (AMPK) activation in rodent models. Humanin operates as a cytoprotective signaling peptide that interacts with extracellular receptors and intracellular BH3-only proteins to modulate apoptotic pathways. Researchers seeking a comprehensive comparison of these mechanisms can consult our central PX1 research library.
Laboratory Reconstitution and Handling Parameters
Lyophilized SS-31 acetate salt is highly soluble in aqueous media. For standard laboratory applications, reconstitution should be performed using sterile Bacteriostatic Water, Sterile Water for Injection, or Phosphate-Buffered Saline (PBS, pH 7.4). Avoid vigorous vortexing; gently swirl the vial until the cake is completely dissolved to prevent mechanical shear stress on the peptide backbone.
For step-by-step mathematical calculations regarding concentration stock preparation, researchers can refer to our dedicated guide on peptide storage and reconstitution. Lyophilized powders should be stored at -20°C upon receipt, while reconstituted liquid stock solutions should be aliquoted into single-use microcentrifuge tubes and maintained at -80°C to eliminate repeated freeze-thaw cycles.
Sourcing and Procurement for Institutional Laboratories
Reliability in supply chain and lot-to-lot consistency are essential for long-term preclinical studies. PX1 Research operates fully within the USA, with primary distribution nodes located in California and Arizona to support fast fulfillment. Orders placed Monday through Friday before 12:00 PM PST feature same-day dispatch to minimize transit delays for climate-sensitive research compounds.
For academic institutions, contract research organizations (CROs), and industrial laboratories requiring multi-gram quantities or custom synthesis lots, our dedicated wholesale laboratory program offers direct access to dedicated account management, bulk lot reservation, and custom analytical validation documentation.
Frequently Asked Questions
What is SS-31 and how is it defined in research settings?
SS-31 (Elamipretide) is a synthetic tetrapeptide (D-Arg-Dmt-Lys-Phe-NH2) studied for its ability to target the inner mitochondrial membrane and interact specifically with cardiolipin. It is supplied exclusively as a research compound for in vitro and animal models.
What is the primary mechanism of action for SS-31 in mitochondrial assays?
In vitro and preclinical studies show that SS-31 selectively binds cardiolipin, stabilizing inner mitochondrial membrane structure, reducing electron leakage, improving oxidative phosphorylation efficiency, and lowering ROS production.
What purity level does PX1 Research guarantee for SS-31?
PX1 Research guarantees a minimum analytical purity of ≥98.0% for SS-31 as verified by HPLC and Mass Spectrometry analysis. A lot-specific Certificate of Analysis (COA) is accessible with every shipment.
How is SS-31 tested for endotoxins?
Every lot of SS-31 undergoes quantitative Chromogenic LAL assay testing in an ISO 17025 accredited laboratory to ensure endotoxin levels remain below 0.01 EU/mg, preventing confounding inflammatory responses in cell culture models.
What solvent is recommended for reconstituting lyophilized SS-31?
Lyophilized SS-31 is readily soluble in sterile water, bacteriostatic water, or sterile PBS (pH 7.4). Gentle agitation by hand is recommended rather than high-speed vortexing.
What are the recommended long-term storage conditions for SS-31?
Lyophilized SS-31 should be stored at -20°C or -80°C in a dry environment. Reconstituted stock solutions should be divided into single-use aliquots and frozen at -80°C to avoid degradation from freeze-thaw cycles.
How does SS-31 compare to MOTS-c and Humanin in lab experiments?
SS-31 is a direct structural stabilizer of cardiolipin on the inner mitochondrial membrane. MOTS-c is a mitochondrial-derived peptide acting on nuclear gene expression and AMPK pathways, while Humanin focuses on cytoprotection and apoptosis signaling.
Can SS-31 be administered to human subjects or used in clinical treatment?
No. SS-31 provided by PX1 Research is strictly designated for laboratory research and in vitro experimentation. It is not intended for human or animal therapeutic, diagnostic, or clinical application.
What analytical documentation accompanies PX1 Research peptides?
Each shipment includes a lot-specific Certificate of Analysis (COA) containing raw HPLC chromatograms, Mass Spectrometry spectra, sequence verification, and endotoxin assay results.
Where are PX1 Research peptides manufactured and dispatched from?
All PX1 Research peptides are synthesized in USA-based GMP-compliant facilities and dispatched from fulfillment hubs in California and Arizona with same-day shipping available Monday through Friday.
What is the molecular weight and chemical formula of SS-31?
SS-31 (Elamipretide free base) has a molecular formula of C32H49N9O5 and a molecular weight of approximately 639.80 g/mol (typically supplied as an acetate salt).
How do I establish institutional pricing or bulk order fulfillment for SS-31?
Institutional accounts and high-volume laboratories can request custom lot reservations and volume discounts through the PX1 Research wholesale portal.
All products are sold strictly for laboratory and research use only. Not for human or veterinary use, diagnosis, treatment or consumption. Statements have not been evaluated by the FDA.