Aliquot
A measured portion removed from a larger laboratory sample or solution.
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A–Z peptide research glossary
Plain-language definitions for COAs, HPLC, storage, and the lab terms we use around here.
Showing 53 of 53 definitions
Analyte
The compound or material being identified or measured during an analytical test.
Batch / Lot Number
An identifier connecting a production group with inventory, testing, and research records.
Blank
A control preparation without the target analyte, used to check background response or contamination.
Certificate of Analysis (COA)
A document that reports identifying information, methods, and analytical results for a represented material.
Chain of Custody
The documented possession, transfer, handling, and control history of a sample.
Chromatogram
A plot of detector response over separation time, including peaks used in chromatographic interpretation.
Content Mass
The measured amount of material associated with a sample, reported separately from chromatographic purity.
Detector Response
The analytical instrument signal generated as a compound passes through a detector.
Dilution
A controlled reduction in concentration produced by adding a measured amount of solvent.
Endotoxin
Bacterial lipopolysaccharide measured with a suitable assay and reported in the laboratory’s stated units.
Experimental Model
A defined laboratory system used to study a scientific question under controlled conditions.
Formulation
The composition and physical presentation of a laboratory material, including any documented excipients.
Freeze–Thaw Cycle
One complete transition from frozen to thawed conditions; repeated cycles can affect some research materials.
Gradient Elution
A chromatography method in which the mobile-phase composition changes during the analytical run.
Gravimetric Measurement
A determination based on carefully measured mass.
Half-Life
The time required for a measured amount or signal to decrease by one half under stated conditions.
HPLC
High-performance liquid chromatography, an analytical separation method commonly used to report chromatographic purity.
Identity
Evidence that an analyzed material corresponds to the expected compound or molecular target.
In Vitro
Research performed outside a living organism, commonly in controlled laboratory vessels or systems.
Internal Standard
A known reference added to samples to support consistent analytical measurement.
Journal Article
A scientific report published through an academic or professional journal.
Kinetic Study
Research that evaluates how a process or measured response changes over time.
LAL Assay
Limulus amebocyte lysate testing used to detect or quantify bacterial endotoxins under defined conditions.
Limit of Detection (LOD)
The lowest amount an analytical method can reliably distinguish from background response.
Lyophilized
Freeze-dried material produced by removing water under controlled low-temperature and vacuum conditions.
Mass Spectrometry (MS)
An analytical method that measures mass-to-charge information and can support molecular-identity confirmation.
Method
The documented analytical procedure and conditions used to generate a reported result.
Molecular Weight
The calculated mass of a molecule, commonly expressed in daltons or grams per mole.
Nominal Amount
The labeled or intended amount of material before analytical measurement.
Observed Mass
The amount measured during analysis under the laboratory’s stated method.
Oxidation
A chemical change involving electron loss that can affect the stability of some research materials.
Peak Area
The integrated area beneath a chromatographic peak, used in quantitative or relative analysis.
Peptide
A chain of amino acids connected by peptide bonds.
Purity
The reported proportion attributable to the primary chromatographic component under the stated method and conditions.
Quality Control
Documented checks used to evaluate consistency, records, processes, or analytical performance.
Quantitation
The analytical determination of how much of a measured compound is present.
Reconstitution
The controlled addition of a compatible laboratory solvent to a dry research material.
Reference Standard
A characterized material used for comparison, identification, calibration, or method suitability.
Research Use Only (RUO)
A designation restricting a material to laboratory research and excluding human, veterinary, diagnostic, or therapeutic use.
Retention Time
The elapsed time at which an analyte or peak is observed during a chromatographic method.
Sequence
The ordered arrangement of amino acids in a peptide.
Specification
A predefined acceptance criterion applied to a material, method, or reported result.
Stability
The capacity of a material to retain defined characteristics under stated conditions and time.
System Suitability
Checks performed to confirm an analytical system is operating acceptably before or during testing.
Traceability
The ability to connect a product, document, order, and research record through reliable identifiers.
Uncertainty
A stated range or estimate describing limitations in a measurement result.
Validation
Documented evidence that a method or process is suitable for its intended purpose.
Verification
Confirmation that a stated requirement, record, or result has been checked.
Working Solution
A prepared laboratory solution used at the concentration required for a specific procedure.
X-Axis
The horizontal axis of a graph; on a chromatogram it commonly represents retention time.
Yield
The amount of material recovered or produced relative to a stated theoretical or starting amount.
Zwitterion
A molecule carrying both positive and negative charges while remaining electrically neutral overall.