> For the complete documentation index, see [llms.txt](https://peptara-labs.gitbook.io/peptaralabs-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://peptara-labs.gitbook.io/peptaralabs-docs/05-glossary.md). # 05 glossary This glossary defines the terms you will encounter on product pages, certificates of analysis, and reconstitution references at [Peptara Labs](https://www.peptaralabs.io/). Definitions are plain and methodological. They describe what each term means, not what to do with any compound. Peptides sold here are research compounds, not approved medicines. The entries below are educational and do not constitute dosing, administration, or usage guidance. ## A **Bacteriostatic water.** Sterile water containing a small amount of preservative that inhibits the growth of bacteria, used as a diluent for reconstituting lyophilized powders in laboratory settings. The preservative is what distinguishes it from plain sterile water. ## C **Certificate of Analysis (COA).** A document issued by a testing laboratory that reports the measured properties of a specific production batch, typically covering purity, identity, sterility, endotoxin level, and heavy-metal content. Each Peptara Labs batch ships with its own third-party COA, viewable on the [COA page](https://www.peptaralabs.io/coa). ## E **Endotoxin.** A component of the outer membrane of certain bacteria that can remain present even after the bacteria themselves are removed. Endotoxin testing measures this residue, and a COA reports the result as a quantified level rather than a simple pass or fail. ## G **GLP-1.** Short for glucagon-like peptide-1, a naturally occurring signaling peptide. The label is also used as a category name for research peptides whose structure is based on or related to it. ## H **Half-life.** The time it takes for the amount of a substance in a system to fall to half of its starting value. It is a descriptive property of a compound, used to characterize how quickly a substance is cleared, and it is not an instruction for use. **Heavy metals screening.** Laboratory testing that measures trace amounts of metals such as lead, arsenic, cadmium, and mercury in a sample. A COA reports these as measured concentrations to confirm they fall within accepted thresholds. **HPLC.** Short for high-performance liquid chromatography, an analytical technique that separates the components of a sample so each can be measured. It is the standard method used to quantify the purity of a peptide. ## I **Identity testing.** Analysis that confirms a sample is the compound it is labeled as, rather than measuring how much of it is present. It answers the question of what the substance is, and is usually performed by mass spectrometry. ## L **Lyophilized.** Describing a substance that has been freeze-dried into a dry, stable powder by removing water under low temperature and reduced pressure. Research peptides are commonly supplied in lyophilized form for stability during storage and shipping. ## M **Mass spectrometry (LC-MS).** An analytical method that measures the mass of molecules in a sample to confirm identity, often paired with liquid chromatography and written as LC-MS. It is the technique most commonly used for the identity portion of a COA. ## P **Peptide.** A short chain of amino acids linked by peptide bonds, smaller than a protein. The term covers a broad range of compounds defined by their amino-acid sequence. **Purity.** The proportion of a sample that is the intended compound, expressed as a percentage and typically measured by HPLC. A higher figure indicates fewer unintended substances in the sample. ## R **Reconstitution.** The process of dissolving a lyophilized powder in a liquid diluent to return it to a solution. The general method is explained on the [reconstitution page](https://www.peptaralabs.io/reconstitution). As an illustration of the arithmetic only, and not a recommendation: dissolving a 5 mg powder in 2 mL of diluent yields a concentration of 2.5 mg per mL. ## S **Sterility.** The condition of being free from viable microorganisms. Sterility testing checks a sample for microbial growth, and the result appears on the COA. ## U **U-100 insulin units.** The unit markings on a standard U-100 insulin syringe, where the barrel is divided so that 100 units equals 1 mL. The scale is a volume measurement printed on the syringe, used to read off small liquid volumes, and the unit markings themselves carry no dosing meaning. ## Further reading For batch-specific test results, see the [Certificate of Analysis page](https://www.peptaralabs.io/coa). For the full catalog and per-milligram pricing, visit [Peptara Labs](https://www.peptaralabs.io/). --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. 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