Cell lines can be grown in 2D (2-Dimensional) and 3D (3-Dimensional) conditions.
Cell culture refers to the process of growing cells under controlled conditions outside their natural environment. Cell lines derived from cancer tissues are used in research as a model to understand the physiology of cancers and also identify new treatment strategies. These cell lines can be grown in 2D (2-Dimensional) and 3D (3-Dimensional) conditions. 2D cultures involve growing cells in a flat surface like petridishes or flasks where they grow as monolayers. A 3D culture is an artificial environment in which the cells are allowed to grow and interact with the surrounding in three dimensions. They grow as spheroids and they mimic the cells inside our body. 2D cell cultures have been used since long time and 3D cultures are a recent trend and are better models to study solid tumors. Various assays are performed in pre-clinical research using these culturing techniques to test the efficacy of anti cancer activity of a novel drug. Once the efficacy is proven, they go on to clinical trials and finally after clearing all the trials they are approved for clinical use. Analyzing cell culture phases of a cell line forms an important step before performing any assay. Cell culture phases are divided into Lag phase, Log phase, Stationery phase and Death/ Decline phase.
In the Lag phase, cells do not divide and during this phase the cells adapt to culture conditions. In the log phase, cells proliferate actively. In the stationery phase, cell proliferation slows down as the cells are confluent. In the Decline/Death phase, the cells begin to die due to the natural progression of cell cycle. It is fundamental to obtain cells in the healthy period of culture phases because it will yield us maximum number of healthy cells and the results will be more reliable. The cell culture phases vary between 2D and 3D cultures. In 3D cultures, more number of viable cells is present and they reach the death phase slowly. The reason behind this is that the cells in 3D grow as spheroids (compact in nature) thereby making more space available for the new cells to grow. In Contrast, 2D cells grow as monolayers and they become confluent as a result they reach the decline phase early. This is due to contact inhibition with each other and won’t be able to grow once they have covered the surface of the flask.
Author details: Ms. V. Barghavi is pursuing her MSc in Human Genetics at the Department of Human Genetics, Faculty of Biomedical Science, Sri Ramachandra Institute of Higher Education and Research, Chennai – 600116, India. E-Mail ID: barcatchme@gmail.com
