Overview
ISO 20391-1:2026 – Biotechnology - Cell counting - Part 1: General requirements and recommendations for cell counting analytical methods defines standard terminology and provides comprehensive guidance on analytical methods for cell counting in biotechnology. Published by the International Organization for Standardization (ISO), this standard covers the measurement and evaluation of cell counts for both cells in suspension (cell concentration) and cells adhered to a substrate (area density). ISO 20391-1:2026 outlines requirements and recommendations for selecting appropriate analytical methods, minimizing variability, managing data, and ensuring accurate reporting. It is applicable to the counting of all cell types, including mammalian and non-mammalian cells such as bacteria and yeast.
Key Topics
ISO 20391-1:2026 addresses several critical aspects of cell counting in biotechnology:
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Standard Terminology: Establishes definitions for key terms such as cell count, cell concentration, area density, direct and indirect cell counting, differential and total cell counting, and others to support uniformity and clarity in communication.
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Cell Counting Methods: Describes primary categories of cell counting:
- Total Cell Counting: Measurement of all cells, regardless of type or attributes.
- Differential Cell Counting: Enumeration of specific cell subsets distinguished by unique attributes.
- Direct Counting: Identifies cells by detecting signals directly from individual cells (e.g., optical, electrical, or mechanical signals).
- Indirect Counting: Measures surrogate signals (such as total DNA content or metabolic activity) and relates them to cell count through mathematical models.
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Measurement Process: Outlines steps such as sample collection, preparation, measurement, and analysis, discussing the potential sources of variability, including manual operations, reagent quality, and sample heterogeneity.
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Fit-for-Purpose Method Selection: Recommends that method selection be driven by the intended application, cell type, sample characteristics, and available instrumentation, considering factors like accuracy, precision, sample preparation, and detection limits.
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Data Analysis and Reporting: Highlights the importance of rigorous data processing, including image analysis, gating, correction for coincidence, and standardized reporting of results to support reproducibility and comparability.
Applications
ISO 20391-1:2026 supports a wide array of applications in biotechnology where reliable and accurate cell counting is essential:
- Biomanufacturing: Monitoring cell concentration in bioreactors for quality assurance in production processes.
- Cell-Based Therapies: Assessing potency and efficacy by quantifying viable and total cells in therapy products.
- Bioassays and Research: Standardized cell enumeration enables normalization and comparison of experimental results.
- Clinical Diagnostics: Enables the differential counting of specific cell subpopulations for diagnostic or monitoring purposes.
- Quality Control: Provides a basis for qualification, validation, and ongoing verification of cell counting methods to ensure consistency and regulatory compliance.
The guidance provided by the standard is broadly applicable to laboratories, manufacturers, researchers, and quality assurance professionals involved in cell counting across all domains of biotechnology.
Related Standards
For specialized techniques or sector-specific requirements, users are encouraged to consult other relevant international or national standards in conjunction with ISO 20391-1:2026. These may include:
- ISO 8196-3: Methods for milk and milk products (flow cytometry cell counting).
- ISO 13366-1: Microscopic methods for somatic cell counting in milk.
- ASTM F2149-16, ASTM F2944-12: Standards related to cell evaluation and counting in medical devices and biomaterials.
- DIN 58932: German standards for blood cell enumeration.
- CLSI H44-A2, USP Biological Tests: Standards for laboratory methods in hematology and biological testing.
By defining general requirements and recommendations, ISO 20391-1:2026 supports harmonization, reproducibility, and comparability in cell counting results throughout the biotechnology industry.
Open preview (PDF)Biotechnology — Cell counting — Part 1: General requirements and recommendations for cell counting analytical methods
