TBS [20x, pH 7.4]

TBS [20x] refers to a 20-fold concentrated stock solution of Tris-buffered saline, commonly used in biochemistry and molecular biology for washing and blocking steps in immunoassays like ELISAs and Western blots. It is a saline solution buffered with Tris and is often prepared at a specific pH, typically 7.4 or 7.6.