Nitric Oxide - Griess Assay
Quantification of nitrite/nitrate (NO byproducts) via the Griess method. Indicator of vasodilation.
O que é NITRIC-OXIDE-GRIESS
Uma técnica de análise avançada
Quantification of nitrite/nitrate (NO byproducts) via the Griess method. Indicator of vasodilation.
What sets us apart
We don't hand over a spectrum. We hand over the interpretation.
Any lab can return peaks and numbers. Our report reads the data. Three differences define what we deliver — illustrated below with a real, anonymized case.
Multiple techniques, one integrated report
We don't hand back five loose reports. We cross-reference every technique's results into a single reading — each signal checked against the others — to reach an answer, not a pile of data.
- Contamination investigation — identifying and tracing the source of a foreign species.
- Performance degradation — explaining why a batch behaves outside expectations.
- New supplier validation — proving equivalence before switching.
3 LDPE batches · 4 techniques converge, NMR reveals the difference
In semicrystalline polymer systems, thermomechanical processing variables influence chain conformational dynamics¹. Solid-state NMR resolves chemical environments at the nanometer scale², sensitive to changes not detectable by XRD or FTIR³.
Technical justification anchored in the literature
Every technique choice and every inference in the report is backed by peer-reviewed literature — with citations in the text. The conclusion isn't loose opinion: it's a traceable argument, defensible in an audit and in front of the client.
- Numbered citations linking claim to source
- Official standards and methods referenced per analyte
- Auditable reasoning end to end
Conclusion and expert opinion
The report closes with a clear position, signed by the Principal Investigator: what the data shows, what can't yet be claimed, and the next step. It includes an honest caveat on the limits of inference — what separates a technical opinion from a guess.
- Explicit technical position, not just results
- Inference limits declared honestly
- Next-step recommendation signed by the P.I.
Four techniques confirmed equivalence; only the solid-state NMR revealed the subtle conformational change not distinguishable by conventional QC — a molecular signature consistent with the atypical filtration behavior.
Without the industrial line's parameters, no direct causal correlation can be established — a complementary step is recommended for elucidation.
Aplicações de mercado
Onde a NITRIC-OXIDE-GRIESS entrega resultados
Aplicações de mercado
Pharma
- Nitrite and nitrate quantitation
- iNOS inhibition screening in macrophages
- Anti-inflammatory compound evaluation
- NO-donor and NO-modulator screening
- NO bioavailability assessment in plasma
Materials
- NO release from NO-donor biomaterials
- Vascular biocompatibility studies
- Vasoactive coating characterization
- Bioactive wound dressing evaluation
- Cardiovascular device material screening
Cosmetics
- Skin microcirculation claim support
- Vasoactive ingredient screening
- Anti-redness and soothing active testing
- Formulation-induced inflammatory response
- Microcirculation product development
FAQ
Frequently Asked Questions about the Griess Assay (Nitric Oxide)
Why does the Griess assay measure nitrite instead of nitric oxide directly?
- Nitric oxide (NO) is an unstable, short-lived free radical gas that is difficult to measure directly in a biological sample, so the Griess assay instead measures nitrite (and, with an additional reduction step, nitrate) — the stable breakdown products of NO — as a reliable indirect proxy for how much NO was produced.
What is the chemical basis of the Griess reaction?
- The Griess reaction combines nitrite in the sample with sulfanilamide and N-(1-naphthyl)ethylenediamine reagents in an acidic environment, forming a pink-purple azo dye compound whose color intensity is measured spectrophotometrically and is directly proportional to the nitrite concentration present.
Why are macrophages commonly used in Griess assay studies?
- Macrophages express inducible nitric oxide synthase (iNOS) in response to inflammatory stimuli, producing large amounts of NO as part of the immune response, making stimulated macrophage cultures a standard model for screening anti-inflammatory compounds by their ability to inhibit iNOS-driven NO (and therefore nitrite) production.
Does a positive Griess assay result mean a compound directly causes vasodilation?
- Not necessarily on its own — the Griess assay confirms increased or decreased NO production/availability, which is a necessary but not sufficient piece of evidence for a vasodilation or microcirculation claim; such claims are typically supported by the Griess assay alongside additional functional or in vivo evidence specific to blood vessel or microcirculation response.
Can the Griess assay be used on both cell culture supernatants and biological fluids like plasma?
- Yes — the Griess reaction can be applied to cell culture media to assess NO production by cultured cells, or to biological fluids such as plasma or serum to assess systemic NO bioavailability, with sample preparation adjusted for the specific matrix being tested.
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