Microfabricated apparatus for cell based assays

A method for determining the effect of a test substance on a cellular activity or physical parameter, which method comprises:

• providing an apparatus having
• i) a base plate supporting a plurality of micro-channel elements, each comprising a cell growth chamber, an inlet channel for supplying liquid sample thereto and an outlet channel for removal of liquid sample therefrom;
• ii) a cover plate positioned over said base plate said cover plate extending over said elements so as to define said chambers and connecting channels;
• said cover plate being supplied with holes to provide access to said channels;
• and
• iii) means, incorporated in said cell growth chambers, for cell growth, wherein one or more components of the apparatus are constructed of a gas permeable film or membrane such that CO2-buffered media can be used in the cell growth chamber and oxygen may permeate to the cells for their metabolism during growth;
• b) introducing said cells into said apparatus and causing said cells to be transported to one or more cell growth chambers in said apparatus, wherein said cells adhere to one or more cell growth chambers;
• c) culturing said cells in one or more cell growth chambers;
• d) providing one or more samples of test substances whose effect upon the cells is to be measured under conditions so as to cause said cells to be exposed to said substances, wherein step d) is performed subsequently to step c);
• and
• e) determining the effect of the test substances on said cells by means of optical detection.