After I have stripped the filters then one of my filters lost all the signals even the signals of the MW marker. What is wrong? The protocol for stripping is this: Warm the stripping buffer (62,5mM Tris-HCl pH 6.7 and 2% SDS) to 50C and put the filter in it for 30min at Room Temp (RT). Wash 2X 10min at RT. Block the membrane with 5% non fat dry milk solution. Any ideas? Thank you!