The animal cell culture technique involves the use of primary and secondary cells grown in an artificial environment. The cells grown can be subcategorised into:
Primary Cells: Primary cells are the first cells or culture obtained directly from animal tissues. These cells are slow-growing and possess all characteristics of the original cells or tissues. The culture of primary cells is done to preserve and maintain the growth of cells in artificial conditions that mimic the original physiological condition. The subsequent subculture of primary cells often leads to the introduction of mutations. The morphological characteristics of the primary cell can vary. Most common morphological structures observed microscopically include epithelial, epithelioid, connective tissue and fibroblast cells. Primary cells are difficult to procure as they require cells directly from the source and have a shorter life span. They are more prone to bacterial, fungal and mycoplasma contamination.
Secondary Cells: Secondary cells are obtained after subsequent subculture of the primary cells. These types of cells are long-lasting and can be subjected to several passages. Secondary cells might not directly resemble the parental cells or tissue characteristics, as they might have undergone specific mutational changes during subculturing. In comparison with primary cells, secondary cells are more stable and less prone to contamination.
Similarity between primary and secondary cells:
Both cells can be of two types:
- Anchorage Dependent- Adherent cells that require a surface for growth
- Anchorage Independent- Suspension cells that can float and grow in a liquid medium.
The growth medium used in cells consists of macronutrients and micronutrients that can replicate the physiological environment for their growth.