SAXS
Determine particle size using laboratory or synchrotron SAXS
- Measures
- Mean diameter and size distribution
- Applied to
- Polydisperse iron oxide nanoparticles
Deliverable D3 · Section 4.1
METRINO practical resources
Measurement SOPs, protocols and good-practice guidance
This page brings together METRINO project results, practical guidance for finding the right method, and selected external standards and protocol resources.
Check the scope before use or reuse. Each procedure was developed or evaluated with specific materials, matrices and model systems. Always verify its scope, conditions and limitations in the linked deliverable before applying it to a new system.
New to SOPs? Give me the 30-second version01 · METRINO project results
Find a method through three pathways
Choose the pathway that best matches your sample and measurement question. The linked deliverables remain the authoritative source for every method’s scope, conditions and limitations.
Pathway 1
Characterise a nanomaterial
Filter the catalogue by measurement need. Each card identifies the technique, the materials used to develop or test the procedure, and its section in the D3 good practice guide. D3 also contains broader decision tables: a method or material listed in those tables does not necessarily have a dedicated SOP.
Size and concentration
SAXS
Determine particle number concentration using synchrotron SAXS
- Measures
- Particle number concentration
- Applied to
- Small iron oxide nanoparticles
Deliverable D3 · Section 4.2
AFM + SEM
Evaluate particle dimensions using hybrid microscopy
- Measures
- Lateral dimensions and particle height
- Applied to
- Hafnium dioxide nanoparticles
Deliverable D3 · Section 4.3
MD-AF4
Evaluate nanoparticle size after fractionation
- Measures
- Size distribution in liquid using complementary detectors
- Applied to
- Iron oxide nanoparticles
Deliverable D3 · Section 4.4
DLS
Determine hydrodynamic particle size
- Measures
- Hydrodynamic size and size distribution
- Applied to
- Monodisperse citrate-coated iron oxide nanoparticles
Deliverable D3 · Section 4.5
Surface properties
TGA
Quantify surface coating amount and homogeneity
- Measures
- Organic surface coating amount and homogeneity
- Applied to
- HfO₂, FeraSpin and iron oxide nanoparticles
Deliverable D3 · Section 5.1
ATR-FTIR
Assess surface chemical composition and homogeneity
- Measures
- Chemical composition of nanoparticle surface coatings
- Applied to
- HfO₂ and FeraSpin samples
Deliverable D3 · Section 5.2
XPS
Determine elemental surface composition
- Measures
- Elemental composition of nanoparticle surfaces
- Applied to
- FeraSpin R-like nanoparticle dispersions
Deliverable D3 · Section 5.3
qNMR
Quantify nanoparticle surface ligands
- Measures
- Identity and quantity of surface ligands in solution
- Applied to
- Citrate-stabilised iron oxide nanoparticles
Deliverable D3 · Section 5.4
D3: Good practice guide and repository of tested SOPsAccess the nine procedures and the broader decision tables for size, concentration and surface characterisation. Version 1 · published 13 July 2026 · DOI 10.5281/zenodo.21641655 · CC BY 4.0.
Access Deliverable D3Working with lipid nanoparticles or liposomes?D3 focuses on the procedures catalogued above. The WP2 results page also explains METRINO work on advanced chemical and structural characterisation of lipid-based nanoparticles, including complementary scattering, microscopy and analytical approaches.
Explore WP2 context
Pathway 2
Prepare, separate and characterise nanoparticles in liquid biological matrices
Start with the sample and liquid matrix, then choose an analytical workflow that fits the nanoparticle system and measurement question. For cells, tissues or tissue phantoms, continue to Pathway 3.
Step 1
Prepare and control the sample
D5 provides procedures for spiking, extraction and fractionation in matrices of increasing complexity.
Review sample preparationStep 2
Select an analytical workflow
D6 describes five fractionation, characterisation and direct-analysis workflows for specific nanoparticle classes.
Find an analytical workflowStep 1: Prepare the sample and manage matrix effects
Spiking in PBS and simulated blood mediumSection 4.1
Spiking in 10% fetal bovine serumSection 4.2
Chemical and enzymatic extractionSections 5–6
AF4 fractionation approachesSection 7
D5: Sample preparation and measurement protocolsUse the public report to check sample-specific conditions, limitations and example datasets. Version 2 · published 24 July 2026 · DOI 10.5281/zenodo.21536481 · CC BY 4.0.
Open D5Step 2: Select an analytical workflow
D6 reports validation and performance evidence for selected fractionation methods. It also includes a complementary SAXS good-practice workflow, which is not presented as a rigid SOP.
MD-AF4
Fractionate and characterise lipid nanoparticles
- System
- mRNA-loaded LNPs
- Includes
- Instrument setup, step-by-step procedure and application to biological matrices
Deliverable D6 · Section 5.1
MD-AF4
Fractionate and characterise liposomes
- System
- Small PEGylated and large non-PEGylated liposomes
- Includes
- Quality control, data analysis, limitations and matrix application
Deliverable D6 · Section 5.2
MD-AF4
Fractionate and characterise metal oxide nanoparticles
- System
- Iron oxide and hafnium oxide nanoparticles
- Includes
- Instrument setup, data analysis, critical parameters and limitations
Deliverable D6 · Section 5.3
SEC-MALS
Characterise lipid nanoparticles using SEC-MALS
- System
- Lipid nanoparticles
- Use when
- A faster, simpler separation is appropriate for the sample size and distribution
Deliverable D6 · Section 5.4
SAXS
Analyse nanoparticles directly in biological media
- System
- Nanoparticles with sufficient scattering contrast
- Use when
- Structural information is needed without prior fractionation
Deliverable D6 · Section 5.5
D6: Fractionation and characterisation protocolsAccess the full workflows, performance evidence, limitations and reporting guidance in the public report.
Open D6Pathway 3
Detect, localise or quantify nanoparticles in cells and tissues
Use D7 to identify protocols for preparing biological and synthetic model systems and for measuring nanoparticle uptake or distribution. Use D8 to understand how selected orthogonal techniques performed in the internal interlaboratory comparison.
Prepare biological and synthetic model systems
Epoxy phantom
Prepare homogeneous tissue-mimicking phantoms
- Purpose
- Instrument calibration and controlled nanoparticle concentration
- Model
- Nanoparticle-spiked epoxy phantoms
Deliverable D7 · Preparation protocol
3D tissue model
Build engineered SISmuc cancer models
- Purpose
- Three-dimensional in vitro evaluation
- Model
- SISmuc scaffolds used as engineered tumour models
Deliverable D7 · Preparation protocol
Cartilage model
Prepare chondrocyte pellet and punch models
- Purpose
- Controlled human cell and tissue-like model preparation
- Model
- Human articular chondrocyte pellets and punches
Deliverable D7 · Preparation protocol
Histology
Spike, embed and section animal tissues
- Purpose
- Prepare tissues for spatial and quantitative analysis
- Includes
- Liver, spleen and lung spiking; paraffin embedding, cryosectioning and deparaffinisation
Deliverable D7 · Tissue preparation workflow
Image, localise and quantify
LA-ICP-TOF-MS
Map elemental distributions in two dimensions
- Measures
- Spatially resolved elemental signals and nanoparticle distribution
- Applied to
- Sections of tissue and model samples
Deliverable D7 · Analytical SOP
scICP-MS
Quantify nanoparticle-associated mass in individual cells
- Measures
- Cell-resolved elemental mass
- Critical point
- Transport efficiency and cell integrity require careful control
Deliverable D7 · Analytical SOP
Digestion + ICP-OES
Quantify Group IV metal oxides after digestion
- Measures
- Total elemental content
- Includes
- Microwave digestion using sulfuric acid/peroxide mixtures
Deliverable D7 · Analytical SOP
TPEF
Image nanoparticle distribution in depth
- Measures
- Three-dimensional fluorescence distribution
- Use when
- Deep-tissue optical imaging is required
Deliverable D7 · Imaging SOP
ToF-SIMS
Map surface chemistry and nanoparticle localisation
- Measures
- Spatially resolved chemical signatures
- Use when
- High-resolution surface chemical mapping is required
Deliverable D7 · Imaging SOP
Inverted light microscopy
Assess model morphology alongside nanoparticle measurements
- Measures
- Morphological features of cells and engineered models
- Role
- Complementary structural context for analytical measurements
Deliverable D7 · Imaging protocol
D7: Tissue, tissue-phantom and cellular measurement protocolsAccess the preparation and analytical SOPs for uptake, distribution, imaging and quantification. Version 1 · published 30 April 2026 · DOI 10.5281/zenodo.21537147 · CC BY 4.0.
Access Deliverable D7
D8: Interlaboratory evidence supporting the pathway
The internal ILC compared complementary approaches across increasing biological complexity. It supports method selection and exposes practical limits; it does not make every method interchangeable or universally validated. Version 1 · published 30 April 2026 · DOI 10.5281/zenodo.21641447 · CC BY 4.0.
Epoxy phantoms
SISmuc 3D tumour models
HfO₂-spiked mouse liver
A549 cells
Key interpretation: D8 correlated TPEF, LA-ICP-MS and ToF-SIMS data through a custom image-registration pipeline and found good agreement between LA-ICP-MS and bulk ICP-MS for HfO₂ uptake. Single-cell ICP-MS remained challenging because of low transport efficiency and cell disruption during injection. These limitations should guide reuse.
Before using a METRINO procedure
Four checks for reliable reuse
A procedure is one part of a reliable measurement workflow. Before applying it to a new system, confirm that the measurement question, sample, controls and reporting requirements are appropriate.
Define the measurement questionSpecify the material, matrix, measurand and intended use.
Check the stated scopeCompare your sample with the materials and conditions evaluated.
Follow the controlsApply the stated preparation, calibration and quality requirements.
Report conditions and limitationsDocument settings, treatment steps, limitations and performance.
See the performance dimensions assessed in D6
The dimensions reported depend on the workflow and evidence available.
RecoveryHow much analyte is recovered through the workflow
PrecisionRepeatability and, where assessed, reproducibility
Accuracy and resolutionAgreement with reference values and separation performance
Carryover and uncertaintyResidual sample effects and confidence in reported values
Beyond METRINO
Continue your search
Explore trusted standards bodies, pharmacopoeial resources and complementary protocol libraries relevant to nanomedicine measurement.
The 30-second version
SOPs and standards — the simple version
Think of an SOP as a carefully written recipe for a defined measurement. Protocols and good-practice guides can add context and choices. A formal standard goes further: it is developed through an organised consensus process.
SOPStep-by-step instructions for carrying out a defined process or measurement within a stated scope.
Protocol or good-practice guidePractical guidance combining procedures, choices, controls, data treatment or limitations.
StandardA consensus-built technical document adopted through a formal standards or compendial process.
The key point: METRINO produced procedures and technical evidence. These may support future standardisation, but they are not themselves formal standards.
From a project result to wider consensus
How a procedure may contribute to future standardisation
A documented procedure can support comparative evidence and technical discussion. Formal standardisation still requires an independent consensus and adoption process.
1Documented procedureScope, controls and reporting requirements
2Comparative evidencePerformance studies or interlaboratory work
3Possible consensus pathwayFurther evaluation by the relevant community or body
This pathway is not automatic and does not imply that a METRINO procedure has already been adopted as a formal standard.
Existing standards and consensus pathways
Use these entry points to explore technical committees, test guidance, interlaboratory pathways and pharmacopoeial information.
ISO/TC 229 — Nanotechnologies
Work programme covering terminology, metrology, reference materials, test methods, modelling, and health and safety aspects of nanotechnologies.
CEN/TC 352 — Nanotechnologies
European standards activity on classification, terminology, metrology, instrumentation, test methods, modelling and simulation for nanotechnologies.
ASTM Committee E56 — Nanotechnology
ASTM committee activity related to standards and guidance for nanotechnology, including characterisation and related terminology.
VAMAS TWA 40 — Synthetic Biomaterials
International pre-standardisation activity using collaborative studies and intercomparisons for materials and technologies relevant to biological applications.
OECD Test Guidelines — Physical-chemical properties
Internationally recognised test guidance for physical-chemical properties, including methods that may be relevant when assessing nanomaterials.
European Pharmacopoeia and EDQM Knowledge Database
Official information on European Pharmacopoeia texts, monographs and reference information for medicines and their ingredients.
USP–NF
Compendial standards and supporting information for medicines, dosage forms, drug substances, excipients and related analytical approaches.
Protocol and good-practice libraries
Complement the METRINO deliverables with established assay collections, methods manuals and measurement guidance from trusted organisations.
NCI Nanotechnology Characterization Laboratory
Protocols and capabilities spanning physicochemical characterisation, in vitro analysis and preclinical evaluation of nanotechnology-based products.
EUNCL Assay Cascade
A structured set of physicochemical, in vitro and in vivo assays developed to support characterisation of nanomedicine candidates.
NanoDefine Methods Manual — Part 3
A European methods manual gathering SOPs used within the NanoDefine framework for particle measurement and material classification.
NPL Good Practice Guides
A broad collection of practical measurement guidance published by the UK National Physical Laboratory across multiple technical domains.
nanopartikel.info Operating Instructions
Practical operating instructions and laboratory guidance for selected nanomaterial preparation and measurement activities.
Related METRINO explainers
Build the scientific and regulatory context around the practical resources collected on this page.
External resources are maintained by their respective organisations. Their inclusion provides routes for further exploration and does not imply that every resource was developed, validated or formally endorsed by METRINO.
