25 terms used throughout the library, each explained the way a careful colleague would — clear, specific, and neutral. Definitions describe terms in a research and documentation context; nothing here is medical advice.
A
- Amino acid
- The individual building block of peptides and proteins. Chains of amino acids linked by peptide bonds form peptides.
B
- Batch / Lot
- A single production run of material. A lot number ties a physical vial to its Certificate of Analysis.
C
- Cake collapse
- A cake that has fallen in on itself — denser, lower, slumped to one side, or with a glassy rather than matte surface. A sign the vial's condition changed after drying.
- Certificate of Analysis (COA)
- A laboratory document reporting what a specific batch of material was tested to be — identity, purity, batch, date, and testing lab.
- Chromatogram
- The visual trace of peaks produced by a technique like HPLC. It is the evidence behind a reported purity percentage.
- Compounded medication
- A medication prepared by a licensed pharmacy for a specific patient under a prescription — part of provider-directed care, not research supply.
- Crimp seal
- The aluminium collar holding a vial's rubber stopper against the glass. It should be tight and immovable; one that spins or lifts has not held.
E
- Endotoxin
- A contaminant that standard identity and purity testing does not cover; it must be tested for explicitly if it matters for a study.
H
- HPLC
- High-performance liquid chromatography — a technique used to separate a sample's components and estimate purity.
I
- Identity testing
- Confirming a sample is the sequence it claims to be, commonly using mass spectrometry to match molecular weight.
L
- Lyophilized
- Freeze-dried. Removing water yields a dry powder that is generally more stable than the material in solution.
- Lyophilized cake
- The dry, porous solid left after freeze-drying, holding the shape of the volume it was dried from. Normally a firm disc or plug that stays put when the vial is tilted.
M
- Mass spectrometry
- A technique that measures molecular weight, used to confirm a compound's identity against its expected mass.
O
- Occlusion
- Moisture or gas trapped inside the cake rather than sitting on the glass. Seen as a wet patch, a darker core, or a pocket within an otherwise dry solid — it is the reason a vial can be compromised while the outside of the cake still looks normal.
P
- Peptide
- A short chain of amino acids — smaller than a protein — joined by peptide bonds.
- Peptide bond
- The chemical link that connects one amino acid to the next in a chain.
- Pressure break
- Loss of the vacuum or inert-gas fill a lyophilized vial is sealed under. Often visible as a domed or dimpled stopper, and usually the reason moisture is found inside.
- Professional Use Only (PUO)
- A designation that material is sold for laboratory and research purposes — not as a drug, food, cosmetic, or supplement, and not for human or animal consumption.
- Protein
- A large, folded chain of amino acids. The line between a long peptide and a small protein is a matter of convention.
- Provider-directed care
- Care in which a licensed clinician evaluates a person and takes responsibility for the plan — categorically different from buying research material.
- Purity
- The share of a sample attributable to the target compound versus everything else, commonly reported from HPLC.
R
- Reconstitution
- The general laboratory concept of returning a lyophilized (dry) material to solution. Specifics are set by protocol and product documentation.
S
- Sequence
- The specific order of amino acids in a peptide, which defines its identity.
- Sterility
- The absence of viable contaminating microorganisms. It is a separate test from identity and purity.
T
- Telehealth
- The delivery of licensed healthcare remotely — for example, an online intake and a video visit with a clinician.
Carry the clarity
The words, then the guides.
With the vocabulary in hand, the rest of the library reads easily — from what a peptide is to how to read a certificate. Nothing here is medical advice; health questions belong with a licensed clinician.