Peptide science, explained with rigor

Featured

Start here

• Analytical Testing

  HPLC vs. Mass Spectrometry: What Each Method Tells You

  A practical comparison of HPLC and mass spectrometry for peptide analysis—what each method measures, what it cannot prove alone, and why they are complementary.

• Analytical Testing

  Purity and Identity Are Not the Same

  Why chromatographic purity and molecular identity answer different analytical questions, and why peptide COA review should treat them as complementary evidence.

• Analytical Testing

  How to Read a Peptide Certificate of Analysis

  A field-by-field guide to peptide COAs, including identity, purity, assay, method details, specifications, signatures, and common warning signs.

• Analytical Testing

  HPLC Peptide Purity Testing Explained

  How reversed-phase HPLC separates peptide components, how chromatographic purity is calculated, and why method suitability matters.

• Peptide Chemistry

  The Complete Guide to Peptide Chemistry

  A technical introduction to peptide structure, amino-acid sequence, peptide bonds, synthesis, purification, stability, and analytical characterization.

All articles

Browse the library

• Analytical Testing · 12 min · Aug 14, 2026

  HPLC vs. Mass Spectrometry: What Each Method Tells You

  A practical comparison of HPLC and mass spectrometry for peptide analysis—what each method measures, what it cannot prove alone, and why they are complementary.

• Analytical Testing · 11 min · Aug 14, 2026

  Purity and Identity Are Not the Same

  Why chromatographic purity and molecular identity answer different analytical questions, and why peptide COA review should treat them as complementary evidence.

• Peptide Chemistry · 22–28 min · Aug 1, 2026

  Amino Acids: Structure, Classification, and Chemical Behavior

  A detailed guide to amino-acid structure, side-chain classes, stereochemistry, ionization, and the chemical features that shape peptide behavior.

• Peptide Chemistry · 22–28 min · Aug 1, 2026

  Higher-Order Peptide Structure

  An accessible technical guide to peptide conformation, alpha helices, beta structures, turns, disorder, cyclization, aggregation, and structural analysis.

• Peptide Chemistry · 24–28 min · Aug 1, 2026

  PEGylation of Peptides

  A technical guide to PEG conjugation chemistry, site-selective attachment, polymer architecture, analytical characterization, and quality control for PEG-modified peptides.

• Peptide Chemistry · 22–28 min · Aug 1, 2026

  Peptide Bonds: Formation, Geometry, and Chemical Stability

  An in-depth explanation of peptide-bond formation, resonance, planarity, cis-trans behavior, hydrolysis, and analytical implications.

• Peptide Chemistry · 22–28 min · Aug 1, 2026

  Primary Structure: How Sequence Defines Peptide Identity

  A technical guide to peptide sequence, residue numbering, terminal modifications, sequence variants, molecular mass, and identity confirmation.

• Peptide Chemistry · 22–28 min · Aug 1, 2026

  What Is a Peptide?

  An evidence-based introduction to peptides, amino acids, peptide bonds, sequence, structure, and the differences among peptides, polypeptides, and proteins.

• Analytical Testing · 12 min · Jul 31, 2026

  A Strategy for Peptide Sequence Confirmation

  How intact mass, MS/MS, peptide mapping, composition, and orthogonal methods combine to support peptide sequence identity.

• Analytical Testing · 10 min · Jul 31, 2026

  Accuracy vs. Precision in Peptide Testing

  Why closeness to the true value differs from repeatability and how both are evaluated in analytical validation.

• Analytical Testing · 11 min · Jul 31, 2026

  Adduct Formation in Peptide Mass Spectrometry

  How sodium, potassium, solvents, acids, and matrix components create additional peptide mass-spectral signals.

• Peptide Chemistry · 13 min · Jul 31, 2026

  Advanced Solid-Phase Peptide Synthesis

  How difficult sequences, resin aggregation, pseudoproline building blocks, double coupling, and process monitoring improve SPPS outcomes.

• Analytical Testing · 11 min · Jul 31, 2026

  Amino Acid Analysis for Peptide Characterization

  How hydrolysis, derivatization, separation, and detection are used to assess amino-acid composition and support peptide content.

• Quality Assurance · 12 min · Jul 31, 2026

  Analytical Method Transfer Between Laboratories

  How laboratories demonstrate that a peptide analytical procedure performs comparably after transfer.

• Quality Assurance · 13 min · Jul 31, 2026

  Analytical Method Validation for Peptide Testing

  An introduction to specificity, accuracy, precision, range, robustness, system suitability, and lifecycle control for peptide analytical methods.

• Analytical Testing · 11 min · Jul 31, 2026

  Analytical Specificity for Peptide Methods

  How a method distinguishes the target peptide from impurities, degradants, excipients, and matrix components.

• Quality Assurance · 12 min · Jul 31, 2026

  Batch-to-Batch Consistency in Peptide Manufacturing

  How specifications, process controls, trend analysis, sampling, and analytical comparability support consistent peptide batches.

• Quality Assurance · 10 min · Jul 31, 2026

  Chain of Custody for Peptide Samples

  How receipt, labeling, transfer, storage, and disposition records protect sample identity and test credibility.

• Analytical Testing · 11 min · Jul 31, 2026

  Chromatographic Resolution Explained

  How resolution describes separation between peptide peaks and how selectivity, efficiency, and retention influence it.

• Analytical Testing · 12 min · Jul 31, 2026

  Chromatography Fundamentals for Peptide Analysis

  A foundational guide to retention, selectivity, efficiency, resolution, mobile phase, and stationary phase behavior in peptide chromatography.

• Storage & Handling · 12 min · Jul 31, 2026

  Cold-Chain Logistics for Research Peptides

  How packaging qualification, temperature logging, lane risk, and excursion assessment protect temperature-sensitive peptide shipments.

• Storage & Handling · 12 min · Jul 31, 2026

  Container-Closure Systems for Peptide Materials

  How vials, stoppers, seals, permeability, extractables, and surface interactions affect peptide stability.

• Quality Assurance · 13 min · Jul 31, 2026

  Data Integrity in Peptide Testing Laboratories

  How audit trails, controlled access, raw-data review, and documented processing protect analytical reliability.

• Peptide Chemistry · 12 min · Jul 31, 2026

  Deamidation and Isomerization in Peptides

  How asparagine and glutamine can undergo deamidation and how aspartate residues can form isoaspartate.

• Analytical Testing · 11 min · Jul 31, 2026

  Detector Linearity in Peptide Analysis

  How analytical response should relate to concentration and why residuals, weighting, and range matter more than correlation alone.

• Peptide Chemistry · 12 min · Jul 31, 2026

  Disulfide Bonds in Peptide Chemistry

  How cysteine pairing, oxidation, reduction, scrambling, and analytical mapping affect disulfide-containing peptides.

• Quality Assurance · 11 min · Jul 31, 2026

  Elemental Impurity Testing for Peptide Materials

  How elemental impurities may enter peptide materials and how ICP-MS or ICP-OES can support risk-based control.

• Quality Assurance · 10 min · Jul 31, 2026

  Endotoxin Testing vs. Sterility Testing

  Why endotoxin and sterility are different quality attributes, how each is tested, and why one result cannot substitute for the other.

• Quality Assurance · 12 min · Jul 31, 2026

  Environmental Monitoring in Controlled Laboratories

  How viable, nonviable, surface, and facility data support contamination control in controlled laboratory environments.

• Quality Assurance · 12 min · Jul 31, 2026

  Forced Degradation Studies for Peptides

  How controlled stress studies reveal degradation pathways and demonstrate stability-indicating analytical methods.

• Quality Assurance · 11 min · Jul 31, 2026

  Good Laboratory Practice Principles

  An educational overview of GLP roles, study plans, raw data, quality assurance, and archival control.

• Storage & Handling · 11 min · Jul 31, 2026

  How to Assess Temperature Excursions

  A structured approach to evaluating time-temperature events affecting stored or shipped peptide materials.

• Analytical Testing · 11 min · Jul 31, 2026

  How to Interpret a Peptide HPLC Chromatogram

  A practical guide to chromatogram axes, retention time, peak area, resolution, integration, system suitability, and common artifacts.

• Analytical Testing · 12 min · Jul 31, 2026

  How to Investigate an Unknown HPLC Peak

  An evidence-based workflow for characterizing new or unexpected peaks in peptide testing.

• Analytical Testing · 12 min · Jul 31, 2026

  How to Read a Peptide Certificate of Analysis

  A field-by-field guide to peptide COAs, including identity, purity, assay, method details, specifications, signatures, and common warning signs.

• Storage & Handling · 10 min · Jul 31, 2026

  How to Store Lyophilized Research Peptides

  A laboratory-focused guide to temperature, moisture, oxygen, light, packaging, and stability documentation for dry peptide materials.

• Quality Assurance · 10 min · Jul 31, 2026

  How to Verify a Certificate of Analysis

  A practical process for confirming COA authenticity, batch linkage, laboratory identity, and report traceability.

• Analytical Testing · 14 min · Jul 31, 2026

  HPLC Method Development for Peptide Analysis

  A structured approach to defining method goals, screening columns, optimizing gradients, and resolving critical peptide impurities.

• Analytical Testing · 13 min · Jul 31, 2026

  HPLC Peptide Purity Testing Explained

  How reversed-phase HPLC separates peptide components, how chromatographic purity is calculated, and why method suitability matters.

• Peptide Chemistry · 11 min · Jul 31, 2026

  Hydrolysis and Peptide-Bond Cleavage

  How water, pH, sequence, and temperature contribute to peptide-bond and side-chain hydrolysis.

• Quality Assurance · 12 min · Jul 31, 2026

  Instrument Calibration and Qualification in Peptide Testing

  How installation, operational, performance, and routine calibration controls support reliable analytical data.

• Quality Assurance · 12 min · Jul 31, 2026

  ISO/IEC 17025 and Laboratory Competence

  How ISO/IEC 17025 addresses impartiality, competence, traceability, validation, and reporting in testing laboratories.

• Analytical Testing · 11 min · Jul 31, 2026

  Isotopic Distributions in Peptide Mass Spectrometry

  How natural isotopes create peptide isotope envelopes and how monoisotopic and average masses differ.

• Quality Assurance · 12 min · Jul 31, 2026

  Laboratory Audits for Peptide Testing

  What to evaluate when auditing third-party peptide testing laboratories, including scope, methods, records, and data integrity.

• Quality Assurance · 11 min · Jul 31, 2026

  Laboratory Document Control

  How SOP approval, versioning, training, obsolescence, and record retention prevent uncontrolled laboratory practices.

• Analytical Testing · 12 min · Jul 31, 2026

  LC-MS vs. MALDI-TOF for Peptide Characterization

  How LC-MS and MALDI-TOF differ in ionization, workflow, quantitation, impurity profiling, throughput, and peptide identity testing.

• Analytical Testing · 12 min · Jul 31, 2026

  Limit of Detection and Limit of Quantitation

  How LOD and LOQ are established for peptide methods and why visual detection is different from reliable quantitation.

• Analytical Testing · 10 min · Jul 31, 2026

  Mass Accuracy in Peptide Mass Spectrometry

  How calibration, resolution, charge assignment, and processing affect the difference between observed and theoretical peptide mass.

• Analytical Testing · 11 min · Jul 31, 2026

  Mass Deconvolution in Peptide Analysis

  How software converts multiply charged peptide spectra into neutral-mass results and where processing errors can occur.

• Analytical Testing · 12 min · Jul 31, 2026

  Mass Spectrometry for Peptide Identity

  How peptide mass spectrometry works, how charge states are interpreted, and what intact mass can and cannot prove.

• Quality Assurance · 12 min · Jul 31, 2026

  Measurement Uncertainty in Peptide Testing

  How uncertainty components influence confidence in assay, impurity, and quantitative peptide results.

• Analytical Testing · 12 min · Jul 31, 2026

  MS/MS Fragmentation of Peptides

  How peptide ions fragment in tandem mass spectrometry and how product-ion series support sequence interpretation.

• Peptide Chemistry · 11 min · Jul 31, 2026

  N-Terminal and C-Terminal Peptide Modifications

  How acetylation, amidation, pyroglutamate formation, and terminal chemistry affect mass, charge, and stability.

• Quality Assurance · 13 min · Jul 31, 2026

  Out-of-Specification and Atypical Laboratory Results

  How laboratories investigate failing, atypical, and out-of-trend peptide test results without testing into compliance.

• Peptide Chemistry · 12 min · Jul 31, 2026

  Oxidation Pathways in Peptides

  How oxygen, light, metals, peroxides, and formulation conditions can oxidize susceptible peptide residues.

• Analytical Testing · 11 min · Jul 31, 2026

  Peak Integration in HPLC

  How chromatographic software defines peak boundaries and why controlled integration is essential for credible peptide purity results.

• Analytical Testing · 11 min · Jul 31, 2026

  Peak Tailing and Fronting in Peptide HPLC

  Why chromatographic peaks become asymmetric and how overload, secondary interactions, and system effects alter peptide results.

• Peptide Chemistry · 12 min · Jul 31, 2026

  Peptide Aggregation and Self-Association

  Why peptides aggregate, how concentration and interfaces contribute, and which analytical methods can detect self-association.

• Analytical Testing · 11 min · Jul 31, 2026

  Peptide Charge States in Electrospray Mass Spectrometry

  Why peptides form multiple charged ions and how charge-state assignment supports deconvolution and mass confirmation.

• Peptide Chemistry · 12 min · Jul 31, 2026

  Peptide Counterions and Salt Forms

  Why acetate, trifluoroacetate, chloride, and other counterions matter for mass, solubility, pH, and analytical interpretation.

• Peptide Chemistry · 13 min · Jul 31, 2026

  Peptide Coupling Chemistry

  How carboxyl activation, coupling reagents, bases, and reaction conditions influence peptide-bond formation and side reactions.

• Analytical Testing · 12 min · Jul 31, 2026

  Peptide Mapping Explained

  How enzymatic or chemical digestion and chromatographic analysis create a peptide fingerprint for identity and structural comparison.

• Peptide Chemistry · 12 min · Jul 31, 2026

  Peptide Solubility Fundamentals

  How charge, hydrophobicity, pH, ionic strength, concentration, and temperature influence peptide dissolution.

• Storage & Handling · 11 min · Jul 31, 2026

  Photostability of Peptide Materials

  How ultraviolet and visible light can affect peptide structure, packaging, and stability testing.

• Quality Assurance · 11 min · Jul 31, 2026

  Proficiency Testing and Interlaboratory Comparisons

  How external comparisons evaluate laboratory performance and reveal method or execution differences.

• Peptide Chemistry · 12 min · Jul 31, 2026

  Protecting Groups in Peptide Synthesis

  Why temporary and side-chain protecting groups are required and how orthogonal chemistry prevents uncontrolled reactions.

• Quality Assurance · 13 min · Jul 31, 2026

  Quality Systems in Peptide Manufacturing

  How document control, deviations, CAPA, change control, supplier qualification, and data integrity support peptide quality.

• Analytical Testing · 11 min · Jul 31, 2026

  Recovery Studies in Peptide Analysis

  How spike-recovery and process-recovery experiments reveal losses from extraction, adsorption, filtration, and matrix effects.

• Quality Assurance · 12 min · Jul 31, 2026

  Reference Standards in Peptide Analysis

  How peptide reference standards are qualified, assigned, stored, tracked, and used for identity and quantitative testing.

• Storage & Handling · 12 min · Jul 31, 2026

  Research Peptide Reconstitution: Laboratory Principles and Controls

  A research-only overview of diluent compatibility, concentration calculations, aseptic handling, mixing, labeling, and post-reconstitution stability.

• Quality Assurance · 11 min · Jul 31, 2026

  Residual Solvent Testing in Peptide Manufacturing

  How synthesis and purification solvents are controlled using risk-based specifications and gas chromatographic analysis.

• Peptide Chemistry · 11 min · Jul 31, 2026

  Resin Selection in Solid-Phase Peptide Synthesis

  How linker chemistry, loading, swelling, and support properties influence peptide assembly and final C-terminal form.

• Analytical Testing · 11 min · Jul 31, 2026

  Robustness Testing for Peptide Methods

  How deliberate small method changes identify critical parameters and operating ranges in peptide analysis.

• Analytical Testing · 10 min · Jul 31, 2026

  Ruggedness and Intermediate Precision

  How analysts, instruments, days, columns, and laboratories contribute to real-world method variability.

• Analytical Testing · 12 min · Jul 31, 2026

  Sample Preparation for Peptide Analysis

  How dissolution, dilution, filtration, adsorption, stability, and container selection influence analytical results.

• Analytical Testing · 10 min · Jul 31, 2026

  Signal-to-Noise in Chromatographic Testing

  How baseline noise and analyte signal affect sensitivity, detection limits, and low-level peptide impurity measurements.

• Peptide Chemistry · 11 min · Jul 31, 2026

  Solid-Phase Peptide Synthesis Explained

  How resin-based peptide assembly works, why protecting groups are required, and where synthesis-related impurities originate.

• Analytical Testing · 12 min · Jul 31, 2026

  System Suitability Testing for Peptide Methods

  How system-suitability criteria verify that an HPLC or LC-MS system is ready to generate acceptable peptide data.

• Peptide Chemistry · 14 min · Jul 31, 2026

  The Complete Guide to Peptide Chemistry

  A technical introduction to peptide structure, amino-acid sequence, peptide bonds, synthesis, purification, stability, and analytical characterization.

• Analytical Testing · 11 min · Jul 31, 2026

  UPLC vs. HPLC for Peptide Analysis

  A practical comparison of HPLC and UPLC for peptide purity, impurity profiling, transfer, speed, pressure, and method performance.

• Analytical Testing · 10 min · Jul 31, 2026

  UV Detection in Peptide HPLC

  How peptide bonds and aromatic residues absorb ultraviolet light and how wavelength selection affects sensitivity and impurity response.

• Storage & Handling · 11 min · Jul 31, 2026

  Water Content and Karl Fischer Testing

  Why residual moisture matters in lyophilized peptides and how Karl Fischer titration differs from loss on drying.

• Quality Assurance · 11 min · Jul 31, 2026

  What Makes an Analytical Method Stability-Indicating?

  How specificity, stress studies, mass balance, impurity resolution, and lifecycle controls establish stability-indicating capability.

No articles match that search.