Scientific Library: results

The discovery of human pluripotent stem cells 10 years ago turned the spotlight on the potential of pluripotent stem cells for personalised cell therapy. The scientific interest then quickly shifted towards the use of these cells for safety pharmacology, drug discovery and disease modelling. For all these purposes, in the mid to long term, properly characterised cell banks will be necessary. 

The characterisation of embryonic (ESC) and induced pluripotent stem cells (IPSC) used for manufacturing requires the development and validation of analytical methods (e.g. flow cytometry, microscopy, QPCR and bioassays). Cell characterisation includes the testing of cell product identity, determination of impurities, and assessment of biological activity and viability. Among the techniques available, flow cytometry is widely used to assess the expression of cell markers. Our laboratory has developed flow cytometry panels dedicated to the characterisation of extracellular and intracellular markers of ESC and IPSC, and to the detection of cell-related impurities. We proposed a method for the validation of flow cytometry panels according to the recommendations of international guidelines on the validation of analytical methods.

IPSC differentiated into cardiomyocytes and MSC-like cells were also used to test the performance of our flow cytometry panels to accurately monitor the manufacturing process of cell products.

In addition to the technical tips, this webinar aims at presenting a critical view on the use of flow cytometry platform for cell characterisation. 

Access the slides of this 45 minutes webinar to learn how to characterise pluripotent stem cells in terms of identity and purity. The analytical performance of the methods developed have been discussed along with the presentation of experimental results obtained during method development, optimisation and/or validation.

Access the slides of this 45 minute webinar to learn how to characterise human mesenchymal stem cells in terms of identity, purity and biological activity. The analytical performance of the methods developed have been discussed along with the presentation of experimental results obtained during method development, optimisation and/or validation.

Human mesenchymal stem cells are widely used in the field of cell therapy, a technology used for the replacement and regeneration of dysfunctional cells by healthy functional cells.

The characterisation of human MSCs used for manufacturing cell therapy products requires the development and validation of analytical methods which meet regulatory requirements. Cell therapy products emerge from a long process of cell culture, differentiation and purification where appropriate cell identity, purity and biological activity (potency) monitoring is mandatory. According to minimal criteria proposed by the International Society for Cellular Therapy (ISCT), MSCs must have the ability to adhere to cell culture plastic surfaces, express some phenotypic markers and differentiate into adipogenic, osteogenic and chondrogenic lineages.

Identity and purity tests can be based on the analysis of one or more specific markers by flow cytometry, fluorescent microscopy and/or qPCR. Biological activity (potency) can be measured using enzymatic assays or immunoassays linked to the relevant biological properties of the cell therapy product. We will present some efficient, optimised approaches developed at Quality Assistance for the characterisation of human mesenchymal stem cells

Access the slides of this 45 minute webinar to learn:

• How to overcome the challenges usually associated to Multiplex assays
• How to select the right technology for your needs

Cytokine profiling is a powerful tool to link the host immune system with disease pathogenesis and/or treatment efficacy. 
The analysis of cytokine expression is frequently required for the characterisation of the status of the immune system, to demonstrate the function of the cells of interest and as an analysis of surrogate markers for in vitro potency testing. 

Classically, the analysis of cytokine expression is performed by ELISA for each separate analyte. 
Multiplex assays allow the simultaneous measurement of multiple cytokines in a sample, increasing the efficiency (less time-consuming and less expensive) and considerably reducing the sample volumes needed.

In the context of a 9 month internal R&D project, we have compared three multiplex technologies for the measurement of cytokines:

• Electrochemiluminescence (ECL, MSD)
• Magnetic beads (Luminex, Merck Millipore) 
• Cytometric Bead Array (FACS Verse, BD)
• The performance of the three assays was evaluated in terms of their accuracy, repeatability, intermediate precision, quantification range and ability to detect cytokines in human PBMC samples.