Fractionation of Carcinoembryonic Antigen and Related Antigens in Normal Adult Feces Using a Gradient Medium Percoll

Abstract Fresh normal human feces were fractionated using Percoll gradients and phosphatidylinositoi-specific phospholipase C. Studies concerning how cells or cell membrane fragments are fractionated with CEA activity indicate that fecal associated CEA activity is not primarily associated with soluble antigens but with whole cells or fragmented cell membranes.