{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.n-hydroxysuccinimide","code":"thing-q408833","url":"https://ver.cy/models/thing/q408833/","name":"N-hydroxysuccinimide","alternateNames":[],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.MAT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"N-hydroxysuccinimide is a cyclic N-hydroxyimide with molecular formula C4H5NO3, commonly used to form activated carboxylic acid esters that facilitate amide-bond formation with primary amines.","purpose":"Enable an agent to identify N-hydroxysuccinimide, assess the suitability of a particular sample, and judge its use as a reagent in carboxyl activation and amide coupling.","scope":{"in":["Molecular identity and identifiers for free N-hydroxysuccinimide, abbreviated NHS","Sample grade, assay, water content, impurities, and analytical evidence","Physical form, dissolution, thermal behavior, and storage condition","Participation in activation chemistry and relationships to NHS esters","Substance-specific hazard evidence and suitability constraints"],"out":["Sulfo-NHS and other substituted succinimide reagents as independent substances","Individual NHS esters, activated surfaces, and NHS-bearing crosslinkers","Carbodiimides such as EDC and their independent substance properties","Complete coupling protocols, manufacturing processes, and reaction optimization","Biomolecule products, conjugate performance, and commercial kit composition"],"boundaries":[]},"distinguishingFeatures":["Match the substance against CAS 6066-82-6, formula C4H5NO3, and molar mass 115.09 g/mol; these identify free NHS rather than an unspecified NHS-containing reagent. [Manufacturer identity record](https://www.thermofisher.com/order/catalog/product/es/en/157270250)","Require structural evidence for the N-hydroxy group on the succinimide framework; a label saying only succinimide does not establish NHS identity.","Check for a sulfonate substituent: sulfo-NHS is a distinct related reagent and must not inherit this substance identity. [NHS and Sulfo-NHS guide](https://www.thermofisher.com/TFS-Assets/LSG/manuals/MAN0011309_NHS_SulfoNHS_UG.pdf)","Distinguish free NHS from an NHS ester carrying an acyl group: the ester is the activated species used in subsequent amine coupling. [Manufacturer coupling guide](https://www.thermofisher.com/TFS-Assets/LSG/manuals/MAN0011309_NHS_SulfoNHS_UG.pdf)"],"structure":{"bundles":[{"id":"nhs-identity-and-boundaries","name":"NHS identity and boundaries","description":"Establish which molecular substance the registry entry denotes.","layers":[{"id":"molecular-identification","name":"Molecular identification","description":"Connect names and identifiers to verified molecular structure.","findings":[{"id":"free-nhs-identity","name":"Free NHS identity","description":"Recognition requires agreement between the chemical structure, substance identifiers, and the sample record.","questions":[{"text":"Does the assigned structure contain the N-hydroxy succinimide framework corresponding to free NHS?","id":"free-nhs-identity-q01","kind":"definition"},{"text":"Which authoritative records establish the CAS, PubChem, and EC cross-references for this identity?","id":"free-nhs-identity-q02","kind":"provenance"}]}]},{"id":"related-reagent-separation","name":"Related reagent separation","description":"Separate free NHS from related substances and functional groups.","findings":[{"id":"derivative-and-mixture-boundary","name":"Derivative and mixture boundary","description":"A derivative or mixture can reference NHS without being the free substance represented by this entry.","questions":[{"text":"Is the material free NHS, sulfo-NHS, succinimide, or an acylated NHS ester?","id":"derivative-and-mixture-boundary-q01","kind":"boundary"},{"text":"Does the reported NHS quantity describe free molecules in a mixture or NHS ester groups attached to another molecule?","id":"derivative-and-mixture-boundary-q02","kind":"measurement"}]}]}]},{"id":"nhs-lot-quality","name":"NHS lot quality","description":"Describe the amount and condition of NHS actually available in a sample.","layers":[{"id":"assay-and-traceability","name":"Assay and traceability","description":"Attach quality claims to the correct lot and analytical basis.","findings":[{"id":"interpretable-nhs-assay","name":"Interpretable NHS assay","description":"Purity must retain its measurement method and reporting basis before it informs reagent calculations.","questions":[{"text":"What NHS assay was measured for this lot, by which method, and on what reporting basis?","id":"interpretable-nhs-assay-q01","kind":"measurement"},{"text":"Which certificate and identity test connect that assay to the container being used?","id":"interpretable-nhs-assay-q02","kind":"provenance"},{"text":"Does the assay support mass correction when calculating moles of NHS?","id":"interpretable-nhs-assay-q03","kind":"action"}]}]},{"id":"water-and-contaminants","name":"Water and contaminants","description":"Record non-NHS constituents that may affect preparation or reaction suitability.","findings":[{"id":"application-relevant-impurities","name":"Application-relevant impurities","description":"Water, residual solvents, and identified impurities require application-specific acceptance criteria.","questions":[{"text":"What water content and residual impurity levels were measured, with which detection limits?","id":"application-relevant-impurities-q01","kind":"measurement"},{"text":"Which impurity limits are justified for the intended NHS activation or coupling application?","id":"application-relevant-impurities-q02","kind":"action"}]}]}]},{"id":"nhs-physical-state","name":"NHS physical state","description":"Capture physical properties under conditions relevant to identification and preparation.","layers":[{"id":"solid-and-thermal-evidence","name":"Solid and thermal evidence","description":"Relate observed sample appearance and thermal transitions to reference evidence.","findings":[{"id":"solid-condition-and-transitions","name":"Solid condition and transitions","description":"Appearance and thermal data support assessment but do not independently prove identity or purity.","questions":[{"text":"What physical form and appearance does this NHS sample exhibit at the recorded temperature?","id":"solid-condition-and-transitions-q01","kind":"measurement"},{"text":"What melting interval is supported by a stated method, and is decomposition reported?","id":"solid-condition-and-transitions-q02","kind":"measurement"},{"text":"Is any reported boiling value experimentally supported at a stated pressure?","id":"solid-condition-and-transitions-q03","kind":"provenance"}]}]},{"id":"dissolution-and-stock-state","name":"Dissolution and stock state","description":"Describe NHS in a specified solvent system.","findings":[{"id":"verified-nhs-solution","name":"Verified NHS solution","description":"A stock preparation needs a supported concentration and an observed dissolution state.","questions":[{"text":"What NHS solubility is supported for the selected solvent composition and temperature?","id":"verified-nhs-solution-q01","kind":"measurement"},{"text":"What is the prepared NHS concentration, and is undissolved material present?","id":"verified-nhs-solution-q02","kind":"measurement"},{"text":"Does the solvent system meet the requirements of the linked activation workflow?","id":"verified-nhs-solution-q03","kind":"action"}]}]}]},{"id":"nhs-reactivity-and-role","name":"NHS reactivity and role","description":"Represent the chemical capabilities that make NHS useful without assigning derivative behavior to free NHS.","layers":[{"id":"carboxyl-activation-role","name":"Carboxyl activation role","description":"Connect free NHS to the activation chemistry in which it participates.","findings":[{"id":"activation-requirements","name":"Activation requirements","description":"NHS can participate with a carbodiimide in forming an NHS ester from a carboxyl-containing substrate. [Manufacturer guide](https://www.thermofisher.com/TFS-Assets/LSG/manuals/MAN0011309_NHS_SulfoNHS_UG.pdf)","questions":[{"text":"Which carboxyl-containing substrate and activating reagent define the intended role of this NHS sample?","id":"activation-requirements-q01","kind":"definition"},{"text":"What evidence supports the required NHS amount and compatibility with the selected conditions?","id":"activation-requirements-q02","kind":"provenance"}]}]},{"id":"ester-and-release-boundary","name":"Ester and release boundary","description":"Track the distinction between free NHS and the activated species.","findings":[{"id":"free-nhs-does-not-prove-coupling","name":"Free NHS does not prove coupling","description":"Both NHS ester hydrolysis and conjugation can release NHS, so NHS release alone does not establish productive conjugation. [Manufacturer reactivity note](https://tools.thermofisher.com/content/sfs/brochures/TR0003-NHS-reactivity-test.pdf)","questions":[{"text":"Does an observed signal quantify free NHS, intact NHS ester, or a combination of species?","id":"free-nhs-does-not-prove-coupling-q01","kind":"measurement"},{"text":"What independent evidence distinguishes productive coupling from ester hydrolysis?","id":"free-nhs-does-not-prove-coupling-q02","kind":"measurement"},{"text":"Which stability claims belong to the particular NHS ester rather than free NHS?","id":"free-nhs-does-not-prove-coupling-q03","kind":"boundary"}]}]}]},{"id":"nhs-preservation-and-handling","name":"NHS preservation and handling","description":"Determine whether the sample remains suitable and what handling evidence applies.","layers":[{"id":"storage-and-reassessment","name":"Storage and reassessment","description":"Connect storage history to supplier instructions and sample evidence.","findings":[{"id":"retained-nhs-suitability","name":"Retained NHS suitability","description":"Storage excursions and prepared-solution age trigger assessment against evidence for the actual material.","questions":[{"text":"What storage conditions and retest or expiry guidance apply to this NHS grade and lot?","id":"retained-nhs-suitability-q01","kind":"provenance"},{"text":"What container, temperature, moisture-exposure, and solution-age history is recorded?","id":"retained-nhs-suitability-q02","kind":"measurement"},{"text":"Which observations or analytical results require retesting or withholding the sample from use?","id":"retained-nhs-suitability-q03","kind":"action"}]}]},{"id":"hazards-and-disposition","name":"Hazards and disposition","description":"Anchor handling and disposal decisions to applicable substance and mixture records.","findings":[{"id":"applicable-nhs-safety-evidence","name":"Applicable NHS safety evidence","description":"Hazard classification, exposure controls, and disposal requirements need dated evidence for the jurisdiction and material form.","questions":[{"text":"Which current SDS establishes the applicable NHS classifications and exposure controls?","id":"applicable-nhs-safety-evidence-q01","kind":"provenance"},{"text":"Are substance-specific exposure limits established, absent from the consulted source, or still unverified?","id":"applicable-nhs-safety-evidence-q02","kind":"boundary"},{"text":"What handling and waste route applies to this NHS solid or its particular solvent and reaction mixture?","id":"applicable-nhs-safety-evidence-q03","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of N-hydroxysuccinimide this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-identifiers","name":"Identifiers and schemes","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these identifiers and schemes hold for the sense of N-hydroxysuccinimide this model covers, and on what evidence?","id":"evidence-identifiers-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of N-hydroxysuccinimide this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these typical measurements hold for the sense of N-hydroxysuccinimide this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of N-hydroxysuccinimide this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of N-hydroxysuccinimide this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Describe N-hydroxysuccinimide and its role in coupling reactions from chemical sources.","Report hazard and storage information from safety data sheets."],"mustNot":["Advise handling it without the protective equipment its safety data sheet calls for.","Advise mixing it with incompatible reagents outside a controlled laboratory.","Help label or crosslink biological agents for harmful purposes."],"requiresHuman":["Approving its use or disposal at a site."]},"ethics":{"considerations":["It is a routine lab reagent; its stakes are worker safety and honest reporting.","Its use in labelling proteins supports research with dual-use potential."],"affectedParties":["Laboratory workers","Researchers relying on the chemistry"]},"owners":{"steward":"The laboratory or operator who holds it; chemical regulators register it.","roles":[],"masterSystems":["Chemical substance registries"]},"relations":[{"target":"Q193430","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.n-hydroxysuccinimide","Wikidata: Q408833 (https://www.wikidata.org/wiki/Q408833)"]},"properties":{"applicability":"required","items":["Chemical identity: Structure identifier; CAS 6066-82-6; formula C4H5NO3","Registry and regulatory cross-references: vr.tr.n-hydroxysuccinimide; verified PubChem and EC records with source dates","NHS assay: % with method and basis, such as mass fraction, dry basis, or chromatographic area","Water and residual impurities: Water in % w/w or mg/kg; identified impurities in % or mg/kg; method and detection limit","Material grade: Supplier-declared grade and application-specific acceptance criteria","Physical condition: Solid or dissolved; appearance; temperature; observed caking or contamination","Solubility and prepared concentration: Solubility in g/L or mol/L with solvent and temperature; stock concentration in mol/L","Thermal behavior: Melting interval in °C; decomposition observation; boiling data only with pressure and evidence","Chemical role: Free reagent; participant in NHS ester formation; released NHS; residual free NHS","Storage and solution history: Container condition; temperature history; opening date; solution solvent, pH, and age","Hazard and exposure status: Dated jurisdiction-specific SDS classification; exposure-limit value and units, or explicitly unestablished"]},"recognition":{"applicability":"required","items":["A white crystalline powder supplied in sealed laboratory bottles.","Identified by label and analysis."]},"capabilities":{"applicability":"required","items":["Resolve an NHS label to a verified chemical identity and reject mismatched derivatives.","Assess a lot against assay, water, impurity, and application requirements.","Calculate an assay-corrected reagent amount when the assay basis supports that calculation.","Evaluate whether a proposed NHS solution is supported by solubility and stability evidence.","Determine whether an activation workflow calls for free NHS, sulfo-NHS, or a preformed NHS ester.","Select handling, storage, retesting, and disposal actions from applicable sample and hazard records."]},"hazards":{"applicability":"required","items":["Can irritate the eyes, skin and airways.","Absorbs moisture and degrades if poorly stored."]},"interfaces":{"applicability":"required","items":["The Globally Harmonized System of Classification and Labelling of Chemicals issued by the United Nations provides the framework for communicating assessed hazards of N-hydroxysuccinimide."]},"context":{"applicability":"required","items":["N-hydroxysuccinimide is used in organic synthesis and bioconjugation work to support the formation of activated esters.","These activated intermediates enable attachment of carboxyl-containing molecules to primary amines in peptide, protein and surface-modification applications.","Laboratory records must distinguish the free reagent from its activated esters because they have different chemical roles and stability."]}},"sources":[{"title":"Wikidata item Q408833: N-hydroxysuccinimide","url":"https://www.wikidata.org/wiki/Q408833","note":"identity and sense of the item"},{"title":"Wikipedia: N-Hydroxysuccinimide","url":"https://en.wikipedia.org/wiki/N-Hydroxysuccinimide","note":"general description of the item"}],"openQuestions":["Which PubChem CID and EC record should be adopted after direct verification against the free NHS structure?","What experimentally supported melting, decomposition, and pressure-qualified boiling data should serve as reference values?","What solvent-specific solubility and free-NHS solution stability data are available across relevant temperatures and pH values?","Which assay methods, water limits, and impurity limits reliably predict suitability for different NHS coupling applications?","What current jurisdiction-specific hazard classifications, exposure limits, and storage requirements apply to free NHS?"],"resources":{"spec":"/models/things/publications/thing-q408833/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q408833/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T11:29:35Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:30+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}