<p>Ponceau Staining of Nitrocellulose or PVDF membranes Theo Laftsoglou</p><p>Materials: Stain  0.1% w/w Ponceau S dye – 0.5 g  1% v/v acetic acid – 5 mL  Make it up to 500 mL with m-Q water</p><p>10x TBS Tris (mw 121.14), final conc 0.5M NaCl (mw 58.44), final conc 1.5M  Disolve 60.55g Tris and 87.66g NaCl in 800ml m-Q water.  Adjust pH to 7.5 with HCl then make up to final volume of 1L. TBS-T  100 ml of 10x TBS  1ml Tween 20  899 ml m-Q water</p><p>Protocol: All steps on the roller at room temperature: 1. Stain the membrane with 5 mL of the Ponceau solution for 5 min. 2. Destain the background with m-Q water – i.e. until you see the band & image.</p><p> Rinse with m-Q water a few times to destain further.  Two (or more) 10 min washes with 20 mL TBS-T for the complete removal of the dye.  Proceed with blocking the membrane as normal. </p><p>Notes  Store solutions at room temperature.  Staining solution can be re-used between 10-40 times.  Do not use with nylon-based filter media. </p>