Developing a single cell integration assay to quantify viral DNA in individual cells

T-cell immunotherapies are showing considerable promise in treating challenging diseases such as blood cancers. These therapies are able to utilise the body’s own immune system to destroy cancerous cells.

The challenge

T-cell immunotherapies are generated by collecting a patient’s own cells and modifying them to target specific cancers, by transferring DNA into the cells using viral vectors.

Ensuring consistency during the transfer of the vectors is critical to controlling product quality. Current methods used to determine the quantity of virus in the cells involve the analysis of viral DNA from a sample pool of cells. While this gives an estimate of the quantity of virus within the sample, it does not account for variations in viral number from cell to cell.

The project

Sphere Fluidics have engineered a new technology to improve the efficiency of transferring viral DNA into cells. The technology involves enclosing single cells in minute drops of fluid, decreasing the distance between the viral DNA and the cell, and increasing the probability of successful DNA transfer.

Image depicting the encapsulation of single cells in water-in-oil picodroplets

Working with Sphere Fluidics, GSK and Cellular Therapeutics, Cell and Gene Therapy Catapult are developing a single cell viral integration assay to quantify the amount of viral DNA that has been transferred into the individual cells. This will allow the new technology to be tested against existing methods.

A single cell in a picodroplet stained with a green dye to prove that it is viable.


The new technology engineered by Sphere Fluidics will provide increased efficiency of transferring viral DNA into cells and will provide manufacturers with the control needed to develop a more consistent cell therapy product.

As well as providing a robust way of testing the new technology, the single cell integration assay will also help T-cell therapy developers understand and monitor the quantity of virus in individual cells. This is not only important in ensuring process effectiveness, but also in safety testing during clinical trials.

The Cell and Gene Therapy Catapult team are world-class and have helped us drive our novel microfluidics technology into the real world of cell therapy generation.

Frank F. Craig, CEO, Sphere Fludics Limited

This collaborative project has offered a great opportunity to develop new technologies, and to improve the efficiency and accuracy of T-cell therapy production. 

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