TEM is the ideal complement to in-vitro assays and molecular techniques in determining the microbiological safety of biological products

Lara Strittmatter, PhD, Electron Microscopy Laboratory Manager, Eurofins BioPharma Product Testing, LaraStrittmatter@eurofinsUS.com

Transmission Electron Microscopy (TEM) is a powerful tool in the biopharmaceutical industry, allowing for high resolution imaging of microscopic structures at the nanometre scale. This technique utilises a beam of electrons that passes through a thin section of a specimen, producing detailed images of the internal structure of the sample. With the ability to magnify samples up to one million times while maintaining every detail, TEM is capable of directly imaging viruses as small as 20-400 nanometres.

One of the key advantages of TEM is its unbiased nature, making it an ideal complement to in-vitro assays and molecular techniques in determining the microbiological safety of biological products. For example, Eurofins can assist clients in characterising cell lines by examining the structural integrity of cells and observing the expression of endogenous retroviral particles present in CHO (Chinese Hamster Ovary) cell lines. Additionally, TEM can be used to enumerate endogenous and viral-like particles in unprocessed bulk from bioreactors, uncovering the presence of any extraneous agents that could have contaminated the cells.

In the expanding field of cell and gene therapy, the production of viral vectors is a crucial aspect of the manufacturing process. The Eurofins Electron Microscopy laboratory can aid in evaluating the size, shape, and purity of viral particles, as well as assessing their capsid content (full vs. empty).

TEM provides scientists with the ability to visualise the morphology of pathogens and contaminants, identifying potential risks associated with the production of biological therapeutics, ultimately leading to the production of safe and effective products for patients. For more information, visit: www.eurofins.com/biopharma-services/product-testing/ services-by-modality/gene-therapy-testing-services/