Cell Potency Assays: Regulatory Perspectives and Emerging Technologies

Cell potency assays measure the biological activity of a cell therapy product relative to a defined reference standard. These assays are required for product release, stability testing, and lot-to-lot consistency in cell and gene therapy manufacturing. This article explains regulatory expectations for potency testing, compares traditional functional assays with emerging molecular and computational methods, and provides practical guidance for selecting and implementing appropriate assays in a diagnostic laboratory setting.

At a Glance

Potency is a critical quality attribute for cell-based medicinal products. Regulatory authorities require evidence that a product demonstrates its intended biological effect through a validated assay that reflects the mechanism of action. The table below summarizes the main potency assay categories, their applications, and key considerations for laboratory implementation.

Regulatory Framework for Potency Testing

Regulatory agencies classify substantially manipulated cell-based products as medicines. These products require extensive characterization covering identity, purity, and potency. Potency is often the most challenging attribute to define and measure because the mechanisms of action for many cell therapies are not fully understood. This difficulty has been described as a persistent challenge in the field of stem cell therapy development.

The regulatory expectation is that potency assays should reflect the intended mechanism of action and demonstrate the product's biological effect. When mechanisms are incompletely characterized, developers must use the best available scientific evidence to design assays that provide meaningful potency information. The Assay Guidance Manual from the National Center for Advancing Translational Sciences provides detailed protocols and considerations for developing and validating various assay formats used in drug development.

Method validation guidance from the U.S. Food and Drug Administration outlines expectations for accuracy, precision, selectivity, sensitivity, reproducibility, and stability in bioanalytical methods. These principles apply to potency assays used for product release and stability testing. Laboratories should align their validation protocols with these expectations even when developing in-house assays.

The Laboratory Quality Management System Handbook from the World Health Organization emphasizes the importance of documented procedures, staff competency, equipment calibration, and quality control in laboratory operations. These principles are directly applicable to potency testing laboratories, where assay performance directly impacts product release decisions.

Mechanism of Action as the Foundation for Assay Design

The design of a potency assay begins with understanding the product's mechanism of action. For cell therapies, this requires identifying the biological pathways through which the product exerts its therapeutic effect. The mechanism may involve direct cell killing, immunomodulation, tissue regeneration, or secretion of bioactive factors.

For T cell-based immunotherapies, the mechanism often involves recognition and elimination of target cells. A cell-based potency assay for a CD3-CD19 bispecific diabody was developed to measure T cell-mediated killing of B cell lymphoma cells. The assay used a cytotoxic T cell line and a fluorescently labeled B cell lymphoma target cell line. Target cell killing released fluorescence proportional to the diabody dose, with greater than 90 percent of target cells killed within two hours of exposure and detectable killing at concentrations as low as 60 pg/mL. This assay met GMP and GLP compliance requirements and provided a quantifiable, reproducible measure of efficacy for batch-to-batch consistency.

For regulatory T cells, the mechanism involves suppression of immune responses through contact-dependent and soluble factor-mediated pathways. Research has shown that CTLA-4 expression on regulatory T cells is critical for their suppressive function, particularly through downregulation of CD80 and CD86 on dendritic cells. A potency assay for regulatory T cell products might measure suppression of effector T cell proliferation or dendritic cell activation, reflecting this mechanism.

For mesenchymal stromal cells, the mechanism of action is often multifactorial. Early clinical trials demonstrated excellent safety profiles, but efficacy results have been inconsistent in later-phase trials. This discrepancy has been attributed to poorly understood mechanisms of MSC therapeutic action. Because multiple attributes may contribute to clinical benefit, a single assay measuring one quality may not adequately reflect potency. An assay matrix combining bioassays and analytical methods is favored for defining MSC potency more adequately.

Traditional Functional Assay Formats

Cytotoxicity Assays

Cytotoxicity assays measure the ability of a product to kill target cells. These assays are widely used for CAR-T cells, T cell engagers, and other immunotherapies. The assay typically involves co-culturing effector cells or molecules with target cells and measuring target cell death.

A validated cell-based potency assay for an anti-CD3-anti-CD19 diabody demonstrated the utility of this approach. The assay used a fluorescent dye to prelabel target lymphoma cells, and T cell-mediated killing released the dye for detection using a fluorometer. The emitted fluorescence was proportional to the dose of the diabody, providing a quantitative potency measurement. This assay format proved suitable for testing purified product, product expressed by transduced cells, and bioactivity in blood samples.

Cytotoxicity assays require careful control of effector-to-target ratios, incubation times, and detection methods. Cell line heterogeneity can hamper standardization and lead to analytical variation. Laboratories should establish clear criteria for cell line maintenance, passage number limits, and viability thresholds to ensure consistent assay performance.

Secretion-Based Assays

Secretion-based assays measure the release of bioactive molecules following product activation. For CAR-T cells, interferon-gamma secretion following co-culture with target cells provides a functional readout of antigen recognition and activation.

A versatile and GMP-compliant bead-based IFN-γ potency assay was developed to address challenges with cell line heterogeneity in traditional co-culture assays. This assay used antigen-loaded streptavidin beads instead of target cell lines. Incubation of beads with recombinant biotinylated antigen produced dose-dependent bead loading. Subsequent incubation of CAR-T cells with antigen-loaded beads triggered dose-dependent IFN-γ secretion, while non-loaded or mock antigen-loaded beads did not trigger significant secretion.

The bead-based assay was fully standardized using fixed amounts of CAR-T cells, antigen loaded onto beads, and antigen-loaded beads per test. A quantitative potency threshold for batch release was established for both fresh and cryopreserved CAR-T cell products. Notably, cryopreserved CAR-T cells yielded lower potency than fresh cells, and potency results correlated with the total amount of CAR-T cells in the test sample. This assay format can be implemented for essentially any antigen of interest.

Reporter Gene Assays

Reporter gene assays use cells engineered to produce a measurable signal in response to product activity. These assays provide quantitative readouts and are suitable for high-throughput applications.

A reporter gene assay was developed to test the potency of human interferon-alpha and interferon-beta using the WISH cell line. The assay measured antiviral activity through a reporter gene construct, providing a quantitative measure of interferon potency. This approach demonstrates how reporter gene assays can replace traditional antiviral assays with more rapid and quantitative formats.

For gene therapy products, reporter gene assays can measure transduction efficiency and transgene expression. A cell-based assay system called EPISSAY was designed for screening epigenetic drugs based on a silenced triple-mutated bacterial nitroreductase fused with red fluorescent protein. Treatment with DNA methyltransferase and histone deacetylase inhibitors increased reporter expression, indicating gene reactivation. The system was used to compare the potency of decitabine before and after liposomal encapsulation, demonstrating its utility for formulation development.

Angiogenesis Assays

For cell therapy candidates with angiogenic mechanisms, the in vitro aortic ring assay provides a functional measure of vascular network formation. A novel application of this assay was developed to assess the angiogenic potential of mesenchymal stromal cells. Thoracic segments of adult rat aortas were isolated, sectioned, and embedded in Matrigel. Fluorophore-labeled cells were co-cultured with developing endothelial networks, and network growth was monitored using microscopy.

First-trimester human umbilical cord-derived perivascular cells migrated toward and integrated with developing aortic ring tubular networks while displaying elongated morphologies. In contrast, bone marrow stromal cells did not show targeted migration and maintained spherical morphologies with limited physical interactions. The perivascular cells contributed to significantly greater radial network growth and network loop formation compared to bone marrow stromal cells and untreated networks. This assay format captures chemotaxis, affinity for developing vasculature, and physical supportive interactions contributing to endothelial network development.

Emerging Molecular and Computational Approaches

Quantitative PCR and Digital PCR

Molecular methods provide precise quantification of vector genomes, transgene expression, and genome editing outcomes. Droplet digital PCR has emerged as a tool for improving the precision and reliability of potency testing for advanced therapy medicinal products. These methods offer advantages in sensitivity, accuracy, and standardization compared to traditional functional assays.

For AAV vectors, potency assessment often involves measuring vector genome copies and transgene expression in transduced cells. A cell-based potency assay using the liver-derived HuH-7 cell line was developed to evaluate infection by self-complementary AAV9 vectors expressing human N-sulfoglucosamine sulfohydrolase. The assay reproducibly expressed the transgene, resulting in measurable enzyme production. Transgene expression and vector genome copies correlated linearly with viral vector dose, with correlation coefficients ranging from 0.71 to 0.95. The assay demonstrated high reliability with intra-assay coefficient of variation below 20 percent and inter-assay reproducibility below 25 percent.

Liquid Chromatography with Tandem Mass Spectrometry

LC-MS/MS provides quantitative measurement of specific proteins or metabolites produced by the product. This approach was used to validate a potency assay for voretigene neparvovec-rzyl, an AAV2 vector expressing human retinal pigment epithelium-specific 65 kDa protein. The assay measured vector transduction in HEK293 cells and the subsequent biological activity of the vector-encoded RPE65 protein in cell lysates. RPE65 converts all-trans-retinol to 11-cis-retinol, which was quantified using LC-MS/MS.

The assay was validated for seven characteristics including system and sample suitability, specificity, linearity, precision, relative accuracy, range, and robustness. The validated assay confirmed relative potency levels of different product lots in the range of 50 to 150 percent of a reference standard defined as 100 percent potent. This represented the first report of validation studies supporting an in vitro cell-based relative potency assay for an AAV vector, used to evaluate lot-to-lot consistency, stability, and comparability following manufacturing changes.

Reporter Gene Assays for Gene Silencing Therapies

For gene silencing therapies targeting dominant genetic diseases, potency assays must measure knockdown of disease gene expression. A framework for potency assay development was described for AAV-based gene silencing therapies targeting facioscapulohumeral muscular dystrophy and Charcot-Marie-Tooth disease type 1A. The approach involved modifying HEK293T cells to increase permissibility to AAV transduction and produce a quantifiable, treatment-responsive readout.

Stable cell lines were created containing the AAV receptor to improve transduction and a Renilla luciferase open reading frame with disease gene sequences in the 3' untranslated region. Disease gene knockdown was quantified by luciferase assay, providing a straightforward framework for potency assay development supporting AAV-mediated and non-viral gene silencing programs.

Single-Cell and Spatial Technologies

Advanced analytical methods are being applied to understand product heterogeneity and identify potency-related attributes. Single-cell RNA sequencing and spatial transcriptomics can resolve cellular states and identify subpopulations with distinct functional properties. These technologies provide insights into the molecular basis of product potency and can inform assay design.

Research on intestinal epithelial cells demonstrated that stemness potential exists beyond the crypt base and resides in the isthmus region, where undifferentiated cells participate in homeostasis and regeneration. This finding challenged the accepted model that Lgr5-positive crypt-base columnar cells represent the sole intestinal stem cell compartment. Such insights have implications for understanding the cellular composition of cell therapy products and identifying potency-related attributes.

For mesenchymal stromal cells, the Decode-Map-Design paradigm has been proposed as a structured translational workflow. Decode integrates single-cell and spatial omics, donor metadata, and orthogonal potency assays to define operational functional states. Map aligns these states with dominant pathobiologic modules in target diseases to enable mechanism-based matching. Design uses atlas-guided isolation, microenvironmental priming, genetic engineering, and standardized cell-free formulation to build products with predefined release criteria.

Artificial Intelligence and Computational Analytics

Computational approaches are being integrated into potency assay development and interpretation. AI-enabled analytics can integrate complex datasets from multiple assay formats and identify patterns predictive of clinical performance. These approaches are particularly relevant for solid tumor immunotherapies, where trafficking, persistence, metabolic fitness, and spatially constrained effector function are key determinants of in vivo performance.

A framework has been proposed for organizing potency assessment into layered panels spanning lean, regulatory compliant release testing through to comprehensive exploratory profiling. This approach provides a practical path toward clinically relevant and regulatorily acceptable potency assurance for solid tumor immunotherapy products.

Assay Matrix Approach for Complex Products

For products with multiple mechanisms of action, a single potency assay may not adequately capture product quality. The assay matrix approach combines multiple bioassays and analytical methods to provide a more complete picture of product potency.

For mesenchymal stromal cells, advanced technologies can achieve quantitative measurement for a range of attributes including immunological, genomic, secretome, phosphorylation, morphological, biomaterial, angiogenic, and metabolic assays. The selection of assays for the matrix should be based on the product's proposed mechanism of action and the attributes most likely to contribute to clinical efficacy.

A potency assay matrix was developed and validated for optimized and consistent manufacture of clinical mesenchymal stem and stromal cells. The matrix approach addressed the challenge of functional heterogeneity among MSC products and provided a framework for release testing that captured multiple aspects of product quality.

For osteogenic potency assessment, a panel of five signature gene biomarkers including ALPL, COL1A2, DCN, ELN, and RUNX2 constituted a proof-of-principle osteogenic potency assay. Assay modification using a potent proprietary osteogenic induction factor and a reference gene pair provided real-time PCR consistency. TGFB2 mRNA induction, important for osteogenic commitment, was readily quantifiable in both bone marrow-derived and adipose tissue-derived MSCs. Combined with DCN, TGFB2 mRNA induction data provided discriminatory power for resolving donor-specific heterogeneity.

Selecting an Appropriate Potency Assay

The selection of a potency assay format depends on product characteristics, mechanism of action, regulatory expectations, and laboratory capabilities. The following decision framework can guide assay selection.

Step 1: Define the Mechanism of Action

Document the proposed mechanism of action based on available scientific evidence. Identify the biological pathways through which the product exerts its therapeutic effect. Consider direct and indirect mechanisms, including cell killing, immunomodulation, tissue regeneration, and secretion of bioactive factors.

Step 2: Identify Critical Quality Attributes

Determine which product attributes are most likely to contribute to clinical efficacy. These attributes may include cell viability, cell number, phenotype, functional activity, and secretion of specific factors. For products with multiple mechanisms, identify the attributes that require measurement through an assay matrix.

Step 3: Evaluate Available Assay Formats

Assess the suitability of different assay formats based on the mechanism of action and critical quality attributes. Consider the following factors:

Step 4: Develop and Validate the Assay

Develop a detailed assay protocol with defined controls, acceptance criteria, and data analysis procedures. Validate the assay for the characteristics relevant to its intended use, including specificity, linearity, precision, accuracy, range, and robustness. Establish a reference standard and define the potency calculation method.

Step 5: Implement and Monitor

Implement the assay in the quality control laboratory with appropriate training and documentation. Monitor assay performance through control charts and trend analysis. Investigate any out-of-trend results and implement corrective actions as needed.

Records and Measurements

Accurate documentation is essential for potency testing. The Laboratory Quality Management System Handbook emphasizes the importance of documented procedures, records, and quality control in laboratory operations. The following records should be maintained for potency assays:

Assay Development Records

Document the scientific rationale for assay design, including the mechanism of action and critical quality attributes. Record the results of feasibility studies, optimization experiments, and validation studies. Maintain version control for assay protocols and reference standards.

Assay Performance Records

Record all assay runs with dates, operators, reagent lots, equipment used, and raw data. Document control results and acceptance criteria. Maintain records of any deviations, investigations, and corrective actions.

Product Testing Records

Document potency results for each product lot tested, including the calculated potency relative to the reference standard. Record the acceptance criteria and the disposition decision for each lot. Maintain stability testing data with time points and storage conditions.

Reference Standard Management

Document the preparation, qualification, storage, and use of reference standards. Record the assigned potency value and the basis for that assignment. Monitor reference standard stability and establish replacement criteria.

Common Failure Patterns in Potency Assay Development

Several recurring challenges can compromise potency assay development and implementation. Recognizing these patterns can help laboratories avoid common pitfalls.

Poor Correlation with Mechanism of Action

Assays that measure attributes unrelated to the product's mechanism of action may not provide meaningful potency information. For example, measuring only cell count or viability for a product whose efficacy depends on immunomodulatory function would not adequately reflect potency. Assay developers should ensure that the measured attribute is biologically relevant to the intended therapeutic effect.

Cell Line Heterogeneity

Cell-based assays using target cell lines can suffer from variability due to cell line drift, passage number effects, and culture conditions. A bead-based IFN-γ potency assay was developed specifically to address this challenge, using antigen-loaded beads instead of target cell lines to improve standardization. Laboratories should establish strict cell line management procedures and monitor assay performance over time.

Inadequate Reference Standards

Potency assays require a well-characterized reference standard against which product lots are compared. Without a stable reference standard, potency values cannot be compared across runs or over time. Reference standards should be qualified for identity, purity, and potency, and their stability should be monitored throughout their use period.

Insufficient Validation

Validation studies that do not adequately assess precision, accuracy, linearity, range, and robustness may not support the intended use of the assay. Regulatory expectations for validation are described in the Bioanalytical Method Validation Guidance from the FDA. Laboratories should design validation studies that address all relevant characteristics and document the results thoroughly.

Overreliance on Single Assays

For products with complex mechanisms of action, a single assay may not capture all aspects of potency. The assay matrix approach is favored for defining MSC potency more adequately, combining multiple bioassays and analytical methods. Laboratories should consider whether a single assay or an assay matrix is appropriate for their product.

Limitations of Current Potency Assay Approaches

Potency assay development for advanced therapy medicinal products presents significant challenges due to the variability of starting materials and the complex mechanisms of action involved. A comprehensive analysis of potency assays used in approved, rejected, and withdrawn cell and gene therapy products identified technical and regulatory challenges across product categories.

Incomplete Understanding of Mechanisms

For many cell therapies, the mechanisms of action are not fully understood, making the definition and validation of suitable potency tests difficult. This challenge is particularly acute for mesenchymal stromal cells, where contradictory efficacy in later-phase clinical trials has been attributed to poorly understood mechanisms of therapeutic action.

Product Heterogeneity

Cell therapy products are inherently heterogeneous due to variability in starting materials, manufacturing processes, and cellular responses. This heterogeneity complicates potency testing because different cell subpopulations may contribute differently to therapeutic efficacy. Single-cell and spatial technologies are being applied to understand this heterogeneity and identify potency-related attributes.

Limited Predictive Value

Potency assays measure product attributes under controlled laboratory conditions, which may not fully predict clinical performance. For solid tumor immunotherapies, trafficking, persistence, metabolic fitness, and spatially constrained effector function are key determinants of in vivo performance that are difficult to capture in standard potency assays. Emerging three-dimensional models, spatial biology, and label-free real-time technologies are being explored as routes to integrate microenvironmental stressors and dynamic single-cell behavior into assay design.

Standardization Challenges

Assay standardization across laboratories remains a significant challenge. Marker instability across laboratories, culture-driven state drift, and assay standardization issues have been identified as principal barriers to implementing potency-based release criteria for MSC products. Collaborative efforts to establish reference standards and harmonized protocols are needed to address these challenges.

Biosafety Considerations for Potency Testing

Potency assays involving viable cells, viral vectors, or human-derived materials require appropriate biosafety measures. The Laboratory Biosafety Manual from the World Health Organization provides guidance on risk assessment, containment levels, and safe handling of biological materials.

Risk Assessment

Conduct a risk assessment for each potency assay, considering the biological agents involved, the procedures performed, and the potential for exposure. Factors to consider include the pathogenicity of any viral vectors, the species of origin for cell lines, and the potential for generation of aerosols during assay procedures.

Containment Levels

Select the appropriate biosafety level based on the risk assessment. Assays involving non-pathogenic cell lines and non-replicating viral vectors may be performed at biosafety level 1 or 2. Assays involving pathogenic agents or replication-competent vectors require higher containment levels.

Personal Protective Equipment

Use appropriate personal protective equipment including gloves, laboratory coats, and eye protection when performing potency assays. Additional protection may be required for procedures that generate aerosols or involve sharps.

Waste Disposal

Dispose of biological waste according to institutional and regulatory requirements. Decontaminate cultures, reagents, and equipment that come into contact with biological materials before disposal or reuse.

Training and Competency

Ensure that laboratory personnel are trained in biosafety procedures and demonstrate competency before performing potency assays independently. The Laboratory Quality Management System Handbook emphasizes the importance of staff competency in laboratory operations.

Professional Escalation Criteria

Laboratory personnel should escalate potency assay issues to appropriate supervisors or quality assurance personnel under the following circumstances:

Out-of-Specification Results

Any potency result that falls outside established acceptance criteria should be escalated immediately. The investigation should determine whether the result reflects a true product quality issue or an assay performance issue.

Out-of-Trend Results

Results that are within acceptance criteria but show unexpected trends should be escalated for review. Trend analysis can identify emerging assay performance issues before they result in out-of-specification results.

Assay Performance Issues

Repeated failures of assay controls, unexpected variability, or poor assay performance should be escalated. These issues may indicate problems with reagents, equipment, cell lines, or operator technique.

Reference Standard Issues

Any concerns about reference standard stability, integrity, or assignment should be escalated. Reference standard issues can compromise the validity of all potency results generated during the affected period.

Regulatory Inquiries

Any inquiries from regulatory authorities regarding potency assay development, validation, or results should be escalated to appropriate management and quality assurance personnel.

Frequently Asked Questions

What is the difference between potency and other product quality attributes?

Potency measures the biological activity of a product relative to a reference standard. Identity confirms that the product is what it claims to be, purity measures the absence of contaminants, and potency demonstrates that the product has the intended biological effect. Potency is often the most challenging attribute to define and measure because it requires understanding the product's mechanism of action.

How is a reference standard for a potency assay established?

A reference standard is a well-characterized material with an assigned potency value against which product lots are compared. The reference standard should be qualified for identity, purity, and potency, and its stability should be monitored throughout its use period. The assigned potency value is typically defined as 100 percent, and product lots are reported as a percentage of the reference standard potency.

What is an assay matrix and when is it needed?

An assay matrix combines multiple bioassays and analytical methods to measure different aspects of product potency. This approach is favored for products with multiple mechanisms of action, such as mesenchymal stromal cells, where a single assay measuring one quality may not adequately reflect potency. The assay matrix can include immunological, genomic, secretome, phosphorylation, morphological, angiogenic, and metabolic assays.

How do regulatory requirements for potency assays differ between regions?

Regulatory frameworks for potency testing are evolving globally. The FDA has issued guidance on potency assurance for cellular and gene therapy products, and European regulators have addressed challenges in potency assay development for cell-based medicinal products. While the fundamental expectation that potency assays reflect the mechanism of action is consistent, specific requirements for validation, reference standards, and acceptance criteria may differ between jurisdictions.

Can molecular methods replace functional potency assays?

Molecular methods such as quantitative PCR and droplet digital PCR provide precise quantification of vector genomes or transgene expression, but they measure quantity instead of biological function. These methods can complement functional assays but may not fully replace them. For products where the mechanism of action is well understood and molecular measurements correlate with functional activity, molecular methods may serve as potency assays. In other cases, a combination of molecular and functional methods may be appropriate.

How should cryopreserved products be handled in potency testing?

Cryopreserved products may yield lower potency results than fresh products, as demonstrated in studies of CAR-T cells where cryopreserved cells yielded lower potency than fresh cells. Potency thresholds for batch release should be established separately for fresh and cryopreserved products. Laboratories should standardize the handling and recovery of cryopreserved samples to minimize variability.

What are the common causes of potency assay variability?

Common causes of variability include cell line heterogeneity, passage number effects, reagent lot differences, operator technique, and environmental factors. The bead-based IFN-γ potency assay was developed specifically to address cell line heterogeneity by using antigen-loaded beads instead of target cell lines. Strict cell line management, reagent qualification, and operator training can reduce variability.

When should a laboratory consider using emerging technologies for potency testing?

Emerging technologies including droplet digital PCR, reporter gene assays, single-cell analysis, and AI-enabled analytics can improve the precision and reliability of potency testing. These technologies may be appropriate when traditional assays lack sensitivity, reproducibility, or biological relevance. The decision to adopt emerging technologies should be based on product characteristics, regulatory expectations, and laboratory capabilities.

Related Diagnostic Guides

• Cytotoxicity Assay: Overview of LDH, MTT, and ATP-Based Methods
• Protein Quantification Assays: Overview of Bradford, BCA, Lowry, and UV Methods
• CRISPR-Cas12a Based Detection of African Swine Fever Virus: A Point-of-Care Molecular Assay for Field Surveillance
• High-Throughput Multiplexed Serological Assays for Emerging Zoonotic Viruses in Livestock Using Bead-Based Flow Cytometric Technology
• Kinase Activity Assay: Methods for Measuring Protein Kinase Activity

References and Further Reading

• Laboratory Quality Management System Handbook. World Health Organization.
• Laboratory Biosafety Manual. World Health Organization.
• Assay Guidance Manual. National Center for Advancing Translational Sciences.
• Bioanalytical Method Validation Guidance. U.S. Food and Drug Administration.
• NCBI Literature Resources. National Center for Biotechnology Information.
• CTLA-4 control over Foxp3+ regulatory T cell function.. Science (New York, N.Y.), 2008.
• Cell-based potency assay for anti-CD3-anti-CD19 diabody.. Journal of immunological methods, 2025.
• Advancing Potency Assay Development for Advanced Therapy Medicinal Products: A Comprehensive Approach and Regulatory Insights.. Human gene therapy, 2025.
• Isthmus progenitor cells contribute to homeostatic cellular turnover and support regeneration following intestinal injury.. Cell, 2024.
• Validation of a quantitative cell-based relative potency assay for LUXTURNA.. Molecular therapy. Methods & clinical development, 2025.
• Advanced Technologies for Potency Assay Measurement.. Advances in experimental medicine and biology, 2023.
• Single-cell/spatial integration reveals an MES2-like glioblastoma program orchestrated by immune communication and regulatory networks.. Frontiers in immunology, 2025.
• Potency Assays: The 'Bugaboo' of Stem Cell Therapy.. Advances in experimental medicine and biology, 2023.
• Development of &lt,i&gt,in vitro&lt,/i&gt, potency assays for AAV-based gene silencing therapies targeting FSHD and CMT1A.. 2026.
• Plying potency assays for immunotherapy of solid tumors.. 2026.
• Decoding, Mapping, and Designing: A New Paradigm for Harnessing Umbilical Cord Mesenchymal Stem Cell Heterogeneity in Obstetric Precision Therapy.. 2026.
• A versatile and GMP-compliant bead-based IFN-γ potency assay for standardized quality control and release testing of CAR-T cell drug products.. 2026.
• Assessing the biopotency of the rAAV9 vector In Vitro.. 2026.
• Paclitaxel and B7-H6 knockdown inhibit HepG2 hepatocellular carcinoma cell viability and migration, while enhancing apoptosis and cell cycle arrest.. 2026.
• Development and validation of a novel cell-based assay for potency determination of human parathyroid hormone (PTH).. Journal of Pharmaceutical and Biomedical Analysis, 2014.
• Angiogenic potency evaluation of cell therapy candidates by a novel application of the in vitro aortic ring assay. Stem cell research & therapeutics, 2017.
• WISH cell line: from the antiviral system to a novel reporter gene assay to test the potency of human IFN-α and IFN-β.. JIM - Journal of Immunological Methods, 2012.
• Qualifying Osteogenic Potency Assay Metrics for Human Multipotent Stromal Cells: TGF-β2 a Telling Eligible Biomarker. Cells, 2020.
• Development of a novel cell-based assay system EPISSAY for screening epigenetic drugs and liposome formulated decitabine. BMC Cancer, 2013.
• A novel series of benzothiazepine derivatives as tubulin polymerization inhibitors with anti-tumor potency.. Bioorganic chemistry (Print), 2021.
• Strategy and Application of Viral Potency Assays in Cell and Gene Therapy. Methods in Molecular Biology, 2025.
• Development and validation of a potency assay matrix for optimized and consistent manufacture of clinical mesenchymal stem/stromal cells. Frontiers in Immunology, 2026.
• The challenges of potency assay development for cell-based medicinal products in Europe. Regulatory Rapporteur, 2015.

This article is educational and does not replace validated laboratory procedures, institutional biosafety review, manufacturer instructions, or professional interpretation.