Overview
ISO/TS 19006:2016 (Nanotechnologies) defines a standardized in vitro protocol using the CM-H2DCF-DA assay to evaluate nanoparticle-induced intracellular reactive oxygen species (ROS) production in the RAW 264.7 macrophage cell line. The Technical Specification covers test setup, sample and reagent preparation, control design, flow cytometry analysis and data interpretation for suspensions of nano-objects, nanoparticles, aggregates and agglomerates. The protocol is explicitly limited to the use of 24‑well plates; alternative culture vessels require validated volume and step adjustments.
Key topics and technical requirements
- Scope and applicability: Screening assay for ROS in RAW 264.7 macrophages exposed to nanomaterials; provides a general measure of oxidative stress rather than identification of specific ROS species.
- Materials and equipment: Lists required reagents, instruments (flow cytometer), culture vessels and calibration steps.
- Sample and suspension preparation: Procedures for nanoparticle dispersion, characterization and verification of potential assay interference (e.g., nanoparticle autofluorescence or quenching).
- Reagent and cell preparations: CM-H2DCF-DA handling, cell stock culture, serum removal and verification of healthy cell growth.
- Controls and calibration: Inclusion of negative controls, particle-only controls, dead-cell controls and positive controls (e.g., Sin-1) to detect assay sensitivity and interference.
- Assay limitations and precautions:
- CM-H2DCF-DA is light- and air-sensitive - protect solutions from light and store under inert gas where recommended.
- The assay can generate false negatives (serum deactivation, DCF leakage, short-lived radicals like superoxide/hydroxyl) and false positives (nanoparticle fluorescence or catalytic interactions).
- Rapid post-staining analysis is advised to minimize dye loss/oxidation.
- Data analysis: Flow cytometry gating, interpretation and reporting recommendations; annexes provide alternate cell lines, fluorescence techniques and example data.
Applications and users
ISO/TS 19006:2016 is intended for:
- Nanotoxicology researchers and academic labs performing in vitro screening of nanoparticle-induced oxidative stress.
- Industry and product safety teams evaluating nanomaterial surface chemistries and formulations.
- Contract research organizations (CROs) and preclinical labs conducting comparative or regulatory-supportive testing.
- Environmental health & safety (EHS) groups and regulatory reviewers needing reproducible ROS screening data.
Practical uses include rapid screening of nanoparticle hazards, comparing coatings or formulations for ROS potential, and selecting materials for more detailed mechanistic studies.
Related standards
- ISO/TS 18827 (ESR-based detection of ROS) - complementary method to differentiate specific ROS species and reduce interference-related ambiguity.
- ISO/TS 80004-2 and ISO 10993-5 - referenced terminology and cytotoxicity context.
Keywords: ISO/TS 19006:2016, CM-H2DCF-DA assay, RAW 264.7, ROS, nanoparticle-induced ROS, nanotechnologies, in vitro assay, flow cytometry, nanoparticle interference.