I haven't done it specifically with Bovine retinal cells, but have used human coronary/aortic endothelial cells on transwells. I made up a 0.5% bovine gelatin solution in water and autoclaved it for sterility. When I wanted to plate EC on the transwells, put enough solution to cover the transwell surface for about an hour to pre-coat. Then suction the gelatin solution off and plate your cells.

Dear Eimear,

Gelatine coating could be sufficient, but not so specific. I would recommend to look in the literature which kind of collagen and/or fibronectin could be useful for your endothelial cells, since the matrix proteins of the ECM can also induce barrier properties and thus influences your experimental results. Please also do not forget to accomplish blank studies without the cells across inserts treated before in the same manner as the ones with cells !

best wishes,

Winfried