Cesium Methanesulfonate Recording Solution
140 mm cesium methanesulfonate (Sigma-Aldrich, C1426)
0.5 mm EGTA (Sigma-Aldrich, 03777)
15 mm HEPES (Sigma-Aldrich, H4034)
2 mm MgATP (Sigma-Aldrich, A9187)
0.3 mm NaGTP (Sigma-Aldrich, G8877)
10 mm phosphocreatine-Tris2 (Sigma-Aldrich, P1937)
2 mm QX 314 chloride (Tocris Bioscience, 2313)
2 mm tetramethylammonium chloride (Sigma-Aldrich, 86616)
Dissolve the above listed chemicals with ~70 mL of distilled water in a 100-mL volumetric flask. Remove the stir bar; add water to fill to exactly 100 mL. Stir again, and adjust the pH to 7.25 using CsOH. If necessary, adjust the osmolarity to ~305 mOsm with water. Aliquot solutions into 1–1.5 mL Eppendorf tubes. Store at −80°C until use (within 1 yr).
