Medicago AB Products Are Available Worldwide. For Research Use Only. Tris Buffered Saline (TBS) is isotonic and non-toxic to cells and is suitable for molecular biology. The buffer is commonly used as substance diluent or as wash buffer in immunoassays such as ELISA. It is used in immuno-histochemical staining when the background is high and for diluting alkaline phosphatase or peroxidase-conjugated antibodies in Western blotting.