Cell Culture Quality Control

3 1 2 4 Cell Culture Quality Control Cell culture is a key tool used in a wide range of applications, from disease modeling to biotherapeutic production. Ensuring the quality of cell cultures at all stages of research is crucial to guarantee the reliability and reproducibility of results and the safety and efficacy of cell culture-derived products. In this infographic, we explore the importance of, and key considerations in, cell culture quality control. Despite its importance, cell culture QC has often been neglected due to it being deemed: Bringing cell culture QC to the forefront of scientists’ minds can help to improve the reliability and reproducibility of results, while reducing the time and costs associated with repeating experiments due to invalid or misleading data. Time-consuming Labor-intensive Subjective Unglamorous Quality control (QC) is intrinsically linked with reproducibility. Inconsistencies in cell cultures can make it difficult to reproduce results, which can be an expensive and time-consuming problem. High rates of irreproducible research have previously been reported, with an estimated equivalent of USD $28 billion per year spent on irreproducible preclinical research. Good QC improves confidence in conclusions drawn from cell culture experiments and the quality of the products produced. Poor QC can lead to invalid or misleading data and unsuitable end products, resulting in a lack of reproducibility and wasting vast amounts of time and money. However, initiatives such as the Guidance Document on Good Cell and Tissue Culture Practice 2.0 are helping to increase awareness of the importance of cell culture QC and encourage best practices. An increasing number of journals ask for obligatory cell line authentication data from submitting authors, in a bid to improve the quality of research published using cell cultures. Cell line authenticity is a crucial part of QC. Obtaining cell lines from a trusted source is essential to ensure they are what you think they are. Estimates suggest that ~22.5% of cell cultures are misidentified. Experiments carried out on the wrong cell line can compromise the applicability of results and safety. DNA profiling by short tandem repeat (STR) typing can be used to determine cell line identity (of human cell lines and some other species) and should be carried out when a cell line is received and routinely thereafter. Alternative testing can be carried out by methods including cytochrome C oxidase subunit 1 gene sequencing, PCR, isoenzyme analysis and karyology. Special attention should be paid to the appropriate naming and labeling of cells to prevent misidentification. Known misidentified cell lines are curated in the Register of Misidentified Cell Lines by the International Cell Line Authentication Committee. Cell cultures depend on cell culture media to supply the nutrients necessary to survive and proliferate. Differences in cell culture media components can impact a range of cell characteristics, including growth rate and viability, and bovine serum can be a source of bovine viral diarrhea virus contamination. Using standardized cell culture media and products with a Certificate of Analysis can help to ensure that reagents are free of contaminants and produced according to a set protocol. Fetal bovine serum can vary from batch to batch, so additional testing should be undertaken to assess any behavioral differences between cells grown with different batches. Ensuring cells are free from contamination from bacteria, fungi, yeast, viruses and mycoplasma is important to reduce the impacts these organisms can have on cells and maintain the safety of end products. The way cell cultures are maintained and stored can have significant effects on their behavior and experimental results. Cells should be passaged regularly to prevent overconfluence and its subsequent effects on cell growth rate and metabolism. Low passage cells should be used where possible. Highly passaged cells are more likely to show chromosomal duplications or rearrangements, mutations and epigenetic changes. It is recommended not to use cells after 20–30 passages. For long-term storage, cells should be frozen slowly with a cryoprotective agent such as DMSO to minimize cryoinjury. When needed, cells should be thawed rapidly. Regular screening for contamination should be carried out, including: • Visual examination of cell growth media for changes in color or turbidity • Microscopic examination of cells • Mycoplasma testing by microbial culture or PCR-based detection Mycoplasma are the smallest self-replicating microorganisms. Mycoplasma contamination is a widespread problem, with estimates suggesting that between 5–35% of cell cultures are contaminated with mycoplasma. Although mycoplasma contamination can be difficult to detect, it can significantly affect cellular biology and processes, including: • Cell viability • Growth rate • Gene expression • Metabolism The risk of contamination can be minimized by using good cell culture practices, such as: • Practicing aseptic technique • Maintaining good personal hygiene • Using personal protective equipment • Working in a well-stocked and clutter-free laminar flow hood • Following pipetting best practices Why is quality control key? Quality control considerations Cell line authenticity Media and reagents Microbial contamination Cell handling and storage Sponsored by my name is HEK-293 Hello my name is Caco-2 Hello my name is Hela Hello