Category
Lab Guides
Bacteriostatic Water vs Sterile Water for Peptide Reconstitution
The two diluents differ by exactly one ingredient — 0.9% benzyl alcohol — and that ingredient decides whether a reconstituted vial can be entered once or many times.
How to Read a Peptide Certificate of Analysis (COA): HPLC, MS and Purity
A peptide COA answers two questions — is this the right molecule, and how much of the material is that molecule? Here is how to read every line, and the red flags that should stop an order.
How to Store Peptides: Lyophilized vs Reconstituted, Temperatures, Light and Freeze–Thaw
Peptide storage comes down to four enemies — heat, moisture, light and freeze–thaw cycling — and two regimes: sealed lyophilized powder and reconstituted solution. Here is the working rulebook.
HPLC Purity for Research Peptides: What ≥98% and ≥99% Actually Mean
An HPLC purity percentage is a ratio of chromatogram peak areas, nothing more and nothing less. Here is how it is measured, what ≥98% vs ≥99% buys you, and what the number cannot tell you.
Choosing Syringes and Needles for Peptide Research: Gauge, Volume, Units
A U-100 unit is 0.01 mL of volume, not a fixed mass of peptide. Here is how gauge, barrel size and dead space change measurement accuracy, with worked mcg-per-unit numbers.
Mass Spectrometry and Peptide Identity Confirmation
Mass spectrometry is the identity half of peptide QC: it weighs the molecule and compares the result to theory. Here is how ESI spectra work, and the diagnostic mass shifts worth memorizing.
Peptide Nasal Sprays: How Research Sprays Are Formulated and Stored
A nasal spray's real specification is mass per actuation: concentration times the pump's fixed 0.1 mL volume. Here is how research sprays are built, verified and stored.
Oral Peptides: Capsules, Troches and Why Bioavailability Matters in Research Design
Swallowed peptides face acid, proteases, a tight epithelium and first-pass metabolism. Oral formats still earn their place — but only when the research question is local rather than systemic.
Peptide Reconstitution Math Explained: mg, mL, mcg and Insulin-Syringe Units
The three formulas every peptide reconstitution calculator runs on — concentration, volume-for-amount and the units conversion — worked through with real numbers so you can check any result by hand.
How to Reconstitute Lyophilized Peptides: Step-by-Step Lab Guide with Worked Examples
A step-by-step lab procedure for turning a lyophilized peptide vial into a known-concentration stock solution, with worked concentration math and the mistakes that most often ruin a vial.
How to Read a Peptide Sequence: One-Letter and Three-Letter Codes, Modifications, Amidation
Peptide sequences are written N-terminus first, in one-letter or three-letter code, with modifications flagged at the end they apply to. Here is how to decode a label and turn it into a molecular weight.
Topical Peptides in Cosmetic Research: GHK-Cu, Argireline, Matrixyl and Delivery
Cosmetic research peptides are small for a reason: the stratum corneum stops most molecules above about 500 Da. Here is what permeates, what does not, and how loading percentages convert to real concentration.
What Is Lyophilization and Why Peptides Ship as Powder
Lyophilization — freeze-drying — removes water from a frozen peptide solution by sublimation, leaving a porous cake that is stable for years and dissolves in seconds. Here is how and why.
Aliquoting Peptide Solutions: Vials, Volumes and Avoiding Contamination
Splitting a stock trades a calculable transfer loss for the end of repeated freeze-thaw damage. Below about 100 µL that trade stops paying — here is where the line sits and how to run the split.
How to Choose a Research Peptide Vendor: 9 Checks (COA, Third-Party Testing, Sizes, Support)
Eight of the nine checks that separate a real research peptide supplier from a reseller can be run before you order. Here they are, with the price-per-milligram math most buyers get wrong.
Using ELISA/RIA Kits in Peptide Research: Standards, Range and Sensitivity
Most peptides are too small for a sandwich ELISA, so signal falls as concentration rises. Here is how to build the standard curve, validate the result and avoid inverting the conclusion.
Fluorescent, Biotin and Radiolabeled Peptides: What Each Label Is For
The right label is decided by the instrument you already own. Here is what fluorescent, biotin and radioiodine labels each do, the mass they add, and how to avoid perturbing binding.
Peptide Blends vs Single Vials: Ratios, COA Interpretation and When Researchers Combine
A blend fixes the component ratio at manufacture; a stack leaves it to you. That single difference drives the concentration math, the COA you should demand and the designs each format can support.
Molecular Weight, Moles and Molarity for Peptide Solutions
Molarity is what receptor and culture protocols are written in; mg/mL is what a vial gives you. Three equations connect them — plus the net-peptide-content correction almost everyone skips.
Peptide Stability and Half-Life: Why DAC, PEG and Acetylation Exist
Vial stability and biological half-life are different problems with different solutions. Here is which enzyme each modification blocks, and what the reported half-lives actually are.
Peptide Solubility: Charge, pH, Hydrophobic Sequences and Solvent Choice
A peptide is least soluble where its net charge is zero. Count the charged residues, find which side of neutral the sequence sits on, and the solvent choice follows.
What 'Research Use Only' Means for Peptides in 2026 (and What It Doesn't)
RUO is a labelling and marketing status, not a quality grade or an approval. Here is what the designation asserts, what it explicitly does not, and how compliant supply and record-keeping look.
Shipping Research Peptides: Cold Chain, Summer Heat and What Actually Degrades
Dry powder tolerates a warm truck; aqueous formats do not. Here is the arithmetic behind that difference, plus what to inspect when a shipment lands.
Third-Party Testing for Peptides: Who Tests, What They Test, and How to Verify a Lot
A third-party report is only meaningful if the lab is named, the report is dated, and the lot matches the vial in your hand. Here is what each test measures and how to check one.