Chemical Identity and Physicochemical Properties

DL-Lactic acid, lithium salt (lithium DL-lactate) is the lithium salt of racemic lactic acid, containing both the D-(R)- and L-(S)-enantiomers in equal proportion. Its molecular formula is C₃H₅LiO₃, and it presents as a white to off-white hygroscopic powder that is freely soluble in water, making it convenient for preparation of aqueous stock solutions in laboratory settings.

As a lithium salt, this compound offers improved stability and handling characteristics compared to free lactic acid, which is a viscous liquid. The salt form facilitates accurate gravimetric weighing, precise concentration preparation, and longer shelf-life under appropriate storage conditions. The compound is not flammable under standard laboratory conditions.

The racemic (DL) designation indicates that the material contains both stereoisomers. Researchers requiring stereospecific activity should note this distinction and select enantiopure L-lactate or D-lactate reagents if stereochemical purity is critical for the intended assay.

Storage, Stability, and Safe Handling

Storage: DL-Lactic acid, lithium salt should be stored in a tightly sealed container at room temperature (15–25 °C) in a cool, dry, and well-ventilated area, away from moisture and incompatible materials. Because the powder is hygroscopic, exposure to ambient humidity should be minimized. Desiccant storage is recommended for long-term preservation of reagent quality.

Stability: The compound is expected to be stable under recommended storage conditions for an extended period. Solutions prepared in water should be used promptly or stored at 4 °C to minimize microbial growth and degradation. Always check the product Certificate of Analysis (CoA) for lot-specific expiry and purity data.

Safe Handling: Standard laboratory personal protective equipment (PPE) should be worn when handling this reagent, including lab coat, chemical-resistant gloves, and safety goggles. Avoid inhalation of dust. Lithium compounds may cause irritation to skin, eyes, and the respiratory tract upon excessive exposure. Consult the Safety Data Sheet (SDS) for full hazard classification and first-aid measures before use. Dispose of waste in accordance with local institutional and regulatory guidelines.

Research Applications

DL-Lactic acid, lithium salt is employed across multiple areas of biomedical and biochemical research, primarily as a metabolic substrate and supplemental reagent:

• Energy Metabolism Studies: Lactate is a central metabolite in mammalian physiology, participating in the Cori cycle and serving as a gluconeogenic precursor. Lithium lactate is used to supply exogenous lactate to cell culture systems or isolated tissue preparations to investigate lactate oxidation, gluconeogenesis, and cellular bioenergetics.
• Cell Culture Supplementation: The compound can be added to culture media as an alternative or supplemental carbon source to study how cells metabolize lactate under normoxic and hypoxic conditions, relevant to cancer metabolism and exercise physiology research.
• Enzyme Assays: Lactate-related enzymatic studies, including lactate dehydrogenase (LDH) activity assays, may use lithium lactate as a defined substrate source due to its ease of dissolution and high purity.
• pH Regulation and Buffering Research: Lithium lactate has been explored in formulations requiring controlled pH and ionic composition, including buffer systems in electrophysiology and perfusion experiments.
• Pharmacological and Toxicological Research: As a lithium-containing compound, it may be relevant to studies examining lithium's biological effects, though researchers should distinguish the metabolic effects of the lactate anion from those of the lithium cation.

Preparation of Working Solutions

DL-Lactic acid, lithium salt dissolves readily in water, allowing straightforward preparation of aqueous stock solutions. The following general protocol is recommended:

1. Calculate the required mass: Determine the target concentration (e.g., 100 mM) and volume, then calculate mass using the molecular weight (MW). Confirm the exact MW from the product CoA or SDS.
2. Weigh accurately: Tare an appropriate vessel and weigh the required amount of powder using an analytical balance. Work quickly to minimize moisture absorption.
3. Dissolve: Add approximately 80% of the target volume of ultrapure water (or the appropriate buffer) to the weighed powder and mix gently until fully dissolved.
4. Adjust pH if necessary: For applications sensitive to pH, adjust using dilute HCl or NaOH as appropriate, then bring to final volume.
5. Filter-sterilize: For cell culture use, pass the solution through a 0.22 µm membrane filter under aseptic conditions.
6. Aliquot and store: Prepare single-use aliquots where possible. Store aqueous solutions at 4 °C for short-term use, or at −20 °C for longer-term storage.

Always verify solution stability and compatibility with other media components before use in sensitive assays.

Quality, Purity, and Regulatory Considerations

Purity and Quality Control: Aladdin Scientific's DL-Lactic acid, lithium salt (SKU L104219) is supplied as a research-grade reagent. Each lot is accompanied by a Certificate of Analysis (CoA) specifying purity, appearance, and relevant analytical test results. Researchers are advised to review the CoA before use to confirm suitability for their specific application.

Regulatory Status: This compound is intended for research use only (RUO) and is not approved for human therapeutic, diagnostic, or veterinary use. It must not be used in clinical or food applications without appropriate regulatory authorization.

Lot-to-Lot Consistency: For experiments requiring high reproducibility, note the lot number used and retain a portion of the CoA. When reordering, contact Aladdin Scientific technical support if lot-matched material is required for longitudinal studies.

Incompatibilities: Avoid contact with strong oxidizing agents and strong acids. Lithium salts may react with certain reagents; consult the SDS for a complete incompatibility list before combining with other chemicals in formulation work.