Primary culture refers to the initial growth of cells or tissues taken directly from a living organism. This process involves isolating cells from a specific tissue, such as muscle or skin, and placing them in a controlled environment, typically a laboratory setting. The goal is to study the cells in their natural state, allowing researchers to observe their behavior, growth patterns, and responses to various stimuli. In primary culture, cells maintain many of their original characteristics, making them valuable for research. Unlike cell lines, which are derived from primary cultures and can be continuously propagated, primary cultures have a limited lifespan. This limitation makes them particularly useful for studying specific biological processes and disease mechanisms.