The fluorescein leakage test method

Method Description

Various cell types can form tight junctions when cultured in vitro. In the case of the fluorescein leakage test method, Madin Derby Canine Kidney (MDCK) cells can do this in a manner that is very similar to tight junctions found in epithelial cells in the eye and specifically the cornea. This creates a largely impermeable barrier that most chemicals cannot cross. This is also applies to fluorescein, which is a dye that is normally blocked by MDCK cells. In the method, the MDCK cells are grown to confluence (i.e. there are tight junctions between cells) on porous filters and then exposed to a test chemical. Leakage is then assessed by measuring how much fluorescein passes through the cell layer. As such the method tries to model the disruption of the integrity.
The test method can be used to assess chemicals and substances that might disrupt tight junctions between epithelial cells that make up the cornea and similar constructs within the eye.