Quality & Methods
How Arcadia Diagnostics works: method-first analytical testing of research materials, system suitability, reference standards, and data retention.
What this laboratory does
Arcadia Diagnostics is an analytical testing laboratory. We measure the composition of materials — lyophilized powders, solutions, and sealed vials submitted by their owners — and issue a written report of what was found, under what conditions, and within what limits.
Despite the name, Arcadia Diagnostics is not a clinical laboratory. We do not accept human biological specimens, we do not test for the diagnosis or treatment of disease, and we do not perform diagnostic testing of any kind. CLIA certification governs the testing of human specimens; it does not apply to the analysis of materials, and we neither hold nor claim it.
Our clients are organizations that need to know what is actually in a material they hold: research-material distributors verifying incoming lots, synthesis groups characterizing their own output, and buyers who want an independent measurement rather than a supplier's own paperwork.
We report measurements. We do not interpret what a measurement means for any person, any use, or any decision. That judgment belongs to the client, and we decline requests for dosing, administration, or suitability-for-use guidance in writing.
Method-first
The technical detail is the substance, not the ornament
A number without its method is not a result. A purity figure of 99.2% means nothing until the wavelength, the gradient, the wash step, the loading, and the integration thresholds are known — every one of those variables can move the figure, and several can move it by more than a percentage point.
So our reports are written to be reproduced from, not merely read. For a chromatographic purity determination that means the column chemistry, dimensions, particle size and pore size; the mobile phase compositions including acid or buffer concentration; the full gradient table, flow rate, and column temperature; the sample diluent and concentration; the detection wavelength and integration parameters; and the reporting and disregard thresholds as numbers rather than as a policy. It means the chromatogram itself, at a scale where the baseline, the void, and the region after the main peak are all visible.
Several consequences follow from taking method seriously, and they shape how the work is actually run:
- The gradient is where purity is won or lost. Peptide retention is extraordinarily sensitive to organic modifier, so a shallow, focused gradient — not a longer column — is what separates a deletion sequence from its parent. A run that stops at the main peak never sees residual protecting groups or dimers, so the method carries a high-organic wash and hold.
- Loading is a trade-off, not a setting. Enough mass on-column to see a small impurity at usable signal-to-noise, but not so much that the main peak leaves detector linearity. Where both are needed, the answer is two injections, and the report says so.
- One condition is one condition. Where main-peak homogeneity has been checked under a genuinely orthogonal condition — a different stationary-phase chemistry, a different pH, or a different separation mode — the report gives that result and its conditions. Where it has not, the report says the assessment was made under a single condition only. Changing gradient slope is not orthogonality.
- Identity is measured, not inferred. Accurate mass with the monoisotopic or average convention stated explicitly, the charge states observed, the deconvolution parameters used, and the error given in both daltons and ppm against a stated acceptance criterion. Intact mass confirms elemental composition, not sequence; where sequence was not confirmed by fragmentation, the report does not let "identity: pass" imply that it was.
Quality practice
What runs alongside every sample
These are working controls, not a philosophy statement. Each one produces a record that appears on the report or is retained and available for audit.
Reference standards
Confirmatory identification requires an authentic reference standard, with its source and lot recorded. Where no certified reference material exists for an analyte — the common case for research peptides — the report states that plainly and describes what the identity determination actually rests on, rather than presenting a bare pass.
System suitability
Replicate injection precision, retention-time precision, peak symmetry, resolution of the critical pair, demonstrated signal-to-noise at the reporting threshold, and a blank injection checked for carryover after the highest-load injection. The results as run appear on the report, not merely the acceptance criteria.
Blanks, controls, and recovery
Method blanks carried through the entire preparation, spike recoveries against defined acceptance windows, and positive product controls where the assay chemistry demands one. An endotoxin result without its positive product control recovery is an uncontrolled result and is not issued as one.
Chain of custody
Condition on receipt is recorded before anything is opened: seal state, container integrity, temperature, quantity, and physical description. Custody, storage conditions, and every transfer are documented through analysis to disposition.
Data integrity
Raw instrument data files are retained unaltered and are the record of the analysis; the report is a derived document. Integration is performed against parameters fixed in the method, not selected per chromatogram. Amended reports are identified as amendments and reference what they supersede.
Anomalous and out-of-expectation results
An unexpected result triggers a documented investigation and a confirmatory retest, not a silent re-injection. Where an investigation cannot assign a cause, the report says so and reports the result.
Instrumentation, by technique
Described by what the technique measures
Instrumentation is described here generically and deliberately. We do not name equipment in marketing copy, and we do not list a technique that is not available to the work.
PLACEHOLDER: instrument inventory — make, model, configuration, and qualification status for each installed platform. Delete every technique below that is not performed in-house, or mark it clearly as referred to a subcontract laboratory.
| Reversed-phase HPLC / UPLC with UV or diode-array detection |
Chromatographic purity as area percent, impurity profiling by relative retention time, and peak-purity screening by spectral homogeneity — with the standing caveat that diode-array peak purity detects only co-eluting species whose UV spectra differ, and is blind to deletion analogs, diastereomers, and Leu/Ile variants. Purity · related substances
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|---|---|
| Liquid chromatography–mass spectrometry, electrospray ionization |
Identity confirmation by accurate mass against the theoretical mass computed from the elemental formula, with the raw charge envelope and the deconvoluted spectrum both reported. Ionization efficiency varies by orders of magnitude between related species, so mass-spectrometric peak areas are never used as a purity figure. Identity
|
| Tandem mass spectrometry and accurate-mass full-scan acquisition |
Targeted confirmation by multiple reaction monitoring — retention time against an authentic standard, two or more transitions, and an ion-ratio criterion — and untargeted full-scan screening for compounds that no targeted panel was built to find. Full-scan data files can be re-interrogated later for a newly emergent compound without re-running the sample. Trace confirmation · untargeted screening
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| Inductively coupled plasma mass spectrometry with collision or reaction cell |
Elemental impurities at trace level following closed-vessel microwave acid digestion, with internal standardization, isotope selection and cell modes chosen against known polyatomic interferences, and a method blank digested through the full procedure on every batch. Elemental impurities
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| Photometric endotoxin detection |
Kinetic measurement of the amoebocyte lysate or recombinant cascade reaction against a standard curve, with the correlation coefficient, the dilution tested relative to the maximum valid dilution, and positive product control recovery all reported. Bacterial endotoxin
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| Static headspace gas chromatography |
Residual solvents against the Class 1 and Class 2 target lists, with the explicit limitation that a screen finds only what it targets. Several high-boiling polar solvents are not adequately recovered under standard headspace conditions, and trifluoroacetic acid is not covered by the method at all. Residual solvents
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| Coulometric Karl Fischer titration |
Water content, specific for water, appropriate to the small sample masses available from a lyophilized vial. Reported with replicate results, blank and drift values, and a note that this is not a loss-on-drying figure. Water content
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| Ion chromatography with suppressed conductivity |
Counterion identity and level — trifluoroacetate, acetate, chloride — which for a peptide is often several percent of the vial mass and is invisible to every chromatographic purity method. Counterion
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What appears on every report
A certificate that a reviewing chemist can rely on is a reproducibility document rather than a summary. Every report carries:
- A unique report number, revision status, and page numbering.
- The client's own sample name and lot identifier, quoted as supplied and marked as unverified client information where the laboratory did not verify it.
- Date and condition of receipt, quantity received, and physical description of the material.
- Method or SOP identifier and version, and whether the compendial procedure or a validated alternative was used.
- Results with units, and a reporting limit or limit of quantitation for every non-detect.
- System suitability and control results as run.
- Any deviation from the method, and its effect.
- Sample disposition and retention period.
- A statement that results relate only to the items tested, and a research-use-only statement.
- Analyst, reviewer, and authorized signatory with dates.
On conformity statements: where a report gives a pass or fail, it is against client-supplied, client-owned acceptance criteria, labeled as such, with the decision rule and its treatment of measurement uncertainty documented. Arcadia does not publish a house pass/fail standard for research materials, because a house standard is an implicit claim of fitness for purpose.
PLACEHOLDER: authorized signatory name and title for report release.
PLACEHOLDER: Arcadia's default reporting and disregard thresholds for impurity profiling — confirm the actual SOP values before publishing.
PLACEHOLDER: sample retention period and disposal method.
Accreditation and regulatory status
This section is deliberately explicit, because accreditation is the easiest place in laboratory marketing to create a serious problem with one careless sentence.
Accreditation is scope-limited: an accredited laboratory holds a published scope enumerating each method and each matrix it covers. A general claim of accreditation implies coverage that a scope may not include. For that reason we will either publish a genuine accreditation with the accrediting body, the certificate number, and a link to the public scope, or say nothing about accreditation at all. We will not describe the laboratory as compliant with, conforming to, or aligned to a standard it is not accredited against — there is no self-declared status of that kind.
PLACEHOLDER: ISO/IEC 17025 accreditation body, certificate number, and public scope-of-accreditation URL — or delete this entire block. Do not soften an absent accreditation into "compliant with." Delete it.
PLACEHOLDER: any other accreditation, certification, registration, or license actually held, each with issuing body, number, scope, and expiry. If the list is empty, every credential block on the site is deleted rather than softened.
PLACEHOLDER: state which quality framework the laboratory actually operates under — for example, internal SOP-controlled non-GMP research testing — and delete any implication of GMP status unless and until formally held.
PLACEHOLDER: DEA analytical laboratory registration and state controlled-substance license, required before any controlled-substance-related service page is published.
PLACEHOLDER: legal entity name, state of formation, and registered address.
What we can offer instead of a badge is specificity: published method detail, stated identification criteria, per-analyte detection limits established by validation on file rather than copied from a vendor datasheet, and honest statements of limitation. To a technical buyer that is more informative than a seal, and it is a claim we are entitled to make.
Arcadia Diagnostics provides analytical testing of materials for research and quality-control purposes. Arcadia Diagnostics is not a clinical laboratory, does not test human specimens, and does not provide medical, diagnostic, or therapeutic services. Nothing on this site is medical advice.
Materials are accepted as research-use-only materials. Reports are not a determination of sterility, biological activity, safety, efficacy, or fitness for any use, and do not constitute clinical, diagnostic, or therapeutic validation. Results relate only to the items tested, in the condition received, on the date received.
References to USP General Chapters, ICH guidelines, and other compendial procedures describe the analytical procedures followed. Those standards are drug-product standards and their acceptance criteria do not apply by law to research-use-only articles.
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