Which is NOT a characteristic of primary cells used in tissue engineering?

In the context of primary cells used in tissue engineering, the characteristic that is not applicable is the tendency to lose potency or de-differentiate with too many passages. Primary cells are taken directly from living tissues and often have a limited capacity for division compared to immortalized cell lines. They typically retain their differentiated state, which means they maintain their specific functions for a longer duration after being harvested.

However, it is important to note that primary cells indeed have characteristics such as being differentiated cells harvested from the patient, which reflects their specific functional tasks. They often yield a low number of viable cells due to their limited population doubling potential, and their performance can be influenced by the age of the donor, potentially leading to age-related issues affecting cell behavior and function. The tendency to lose potency or de-differentiate with too many passages is more characteristic of cell lines rather than primary cells, as primary cells tend to maintain their specialized characteristics better in shorter culture periods without extensive manipulation.