Abstract
The placenta is a multifaceted organ, fulfilling critical functions for the fetus and the mother. Therefore, it is a critical regulator of the pregnancy, and its dysfunction leads to diseases, including fetal growth restriction and preeclampsia. Studying the placenta is a difficult task since its existence is transient, and its structure is specific to our species. In vitro differentiation of primary cytotrophoblast isolated from term human placenta has been widely used in the placental research field as it represents a reliable model to study cellular differentiation and function. Direct alternatives include trophoblastic cell lines, explants, and organoids, but this protocol, based on the separation of the cells on a Percoll gradient, presents the advantage of being relatively cheap and easy to perform in every research laboratory. Furthermore, the 2D culture is a flexible method that can be adapted to various experimental conditions (transfection, drug exposure, metabolic study, observations, etc.), allowing mechanistic explorations of cellular processes.