What is a primary cell culture?

A primary cell culture refers to cells that are directly isolated from living tissue and then cultured in a laboratory setting. This process typically involves taking a small sample of tissue, which can come from various sources like animals or plants, and then disaggregating it into individual cells. These cells are then placed in a nutrient medium that allows them to grow and proliferate outside their original environment.

This technique is crucial in biomedical research, as it enables scientists to study cellular functions, interactions, and responses in a controlled setting. Primary cell cultures are often preferred for their ability to maintain characteristics of the original tissue, making them valuable for applications in drug testing, toxicity studies, and understanding disease mechanisms.

The other options relate to different aspects of cell culture. Genetically modified cells refer to those that have been altered for specific research purposes but do not characterize primary cell cultures. Frozen and stored cells relate to the process of cryopreservation, which is a method used to preserve cell lines and not specific to primary cultures. Lastly, cells grown for extended periods typically refer to cell lines, which have undergone several generations of growth and may not retain the same characteristics as primary cells. Thus, the definition and context of primary cell culture is best captured by the selected answer.