Abstract: Apparatus for growing cells or tissue in vitro, which permits a concentration gradient of nutrients to develop through a permeable membrane to which a sample of tissue is attached. The permeable membrane is attached to the bottom end of a cell culture insert that in turn is supported by a flange connected to its upper end on the top of a well containing the nutrients. Restricted movement of the cell culture insert in the well may be facilitated by projections extending off the outer wall surface of the insert so as to avoid capillary action in the space between the well and the insert.

Abstract: Apparatus for growing tissue cultures in vitro, which permits a concentration gradient of nutrients to develop through a permeable membrane to which a sample of tissue is attached. The permeable membrane is attached to the bottom end of a cell culture insert that in turn is supported by a flange connected to its upper end on the top of a well containing the nutrients and is self centered in the well by the arrangement of the sidewalls of the cell culture insert. The self centering feature of the insert minimizes capillary action.