An automated assay apparatus for performing one ore more assay procedures using a liquid reagent and a washer liquid, the apparatus comprises: a reagent supply vessel adapted to be filled with the liquid reagent; a reaction chamber; a plurality of first elastomeric conduits, each comprising a passageway, a first end in communication with said reagent supply vessel, and a second end in communication with said reaction chamber; a valve chassis operable with said first elastomeric conduits to deliver said liquid reagent from said reagent supply vessel to said reaction chamber; said valve chassis comprising upper and lower flanges and left and right support flanges; characterized in that,said valve chasis further comprising a plurality of reagents supply valves each having a side flange and an abutment extending between said lower and upper flanges of said valve chassis; each of said reagents supply valves further comprising a first lower passage way formed in said lower flange of said valve chassis and a first upper passage way formed in said upper flange of said valve chassis; said first upper passage way being substantially aligned with said first lower passageway; a respective first elastomeric conduit extending thru said first lower passage way and said second upper passage way; each of said reagents supply valves further comprising a spring having a first leg engaged with said side flange and a second leg having an end portion; said second leg of said spring being normally biased to pinch said respective first elastomeric conduit against said respective abutment to close said passageway of said first elastomeric conduit to prevent delivery of the liquid reagent to said reaction chamber, and a valve operating unit with drive means activating the plural reagents supply valves individually or all together simultaneously, wherein the valve operating unit is a single drive unit to control all reagents supply valves, wherein the drive means comprises a motor, a shaft, and a cam engaged with said shaft; rotation of said shaft causing rotation of said cam to open the punched first elastomeric conduits and to allow delivery of the liquid reagent to the reactor chamber. a reagent supply vessel adapted to be filled with the liquid reagent; a reaction chamber; a plurality of first elastomeric conduits, each comprising a passageway, a first end in communication with said reagent supply vessel, and a second end in communication with said reaction chamber; a valve chassis operable with said first elastomeric conduits to deliver said liquid reagent from said reagent supply vessel to said reaction chamber; said valve chassis comprising upper and lower flanges and left and right support flanges; characterized in that,said valve chasis further comprising a plurality of reagents supply valves each having a side flange and an abutment extending between said lower and upper flanges of said valve chassis; each of said reagents supply valves further comprising a first lower passage way formed in said lower flange of said valve chassis and a first upper passage way formed in said upper flange of said valve chassis; said first upper passage way being substantially aligned with said first lower passageway; a respective first elastomeric conduit extending thru said first lower passage way and said second upper passage way; each of said reagents supply valves further comprising a spring having a first leg engaged with said side flange and a second leg having an end portion; said second leg of said spring being normally biased to pinch said respective first elastomeric conduit against said respective abutment to close said passageway of said first elastomeric conduit to prevent delivery of the liquid reagent to said reaction chamber, and a valve operating unit with drive means activating the plural reagents supply valves individually or all together simultaneously, wherein the valve operating unit is a single drive unit to control all reagents supply valves, wherein the drive means comprises a motor, a shaft, and a cam engaged with said shaft; rotation of said shaft causing rotation of said cam to open the punched first elastomeric conduits and to allow delivery of the liquid reagent to the reactor chamber.