Container for sample testing

Apparatus for comparative testing of a sample substance comprising:

• a unitary structure including a single row of at least four tubularly shaped compartments joined side by side along said single row, each said compartment having the same cross sectional area, each said compartment including an upper open end and a lower closed end spaced from said upper open end graduated distances such that at least three of said compartments define successively increasing or decreasing volumes as measured from the other of said compartments which is a control compartment;
• a layer of self sealing elastomeric material placed over said open ends for sealing each said compartment from adjacent compartments and from the outside atmosphere;
• a protective layer positioned between said open ends and said elastomeric material;
• a cover connectable to said compartments adjacent said open end, said cover and said upper end of said compartments cooperating to position and compress said elastomeric material and said protective layer, said cover including access openings, one access opening for each compartment, each said access opening in line with its corresponding open end such that a probe may be inserted through each said access opening, said elastomeric material, and said protective layer to enter said compartment;
• and
• at least one level line on each said compartment, each said level line being spaced from said open end a predetermined distance such that at least some of said level lines are spaced different distances from said lower closed end.