SYPRO® Ruby protein blot stain is a highly sensitive, ready-to-use fluorescent stain for proteins on nitrocellulose or PVDF membranes. It is compatible with immunostaining (Western blotting), microsequencing and mass spectrometry. Stained proteins can be viewed with a standard UV transilluminator or with a laser scanner. For optimal sensitivity with Polaroid film, use of the SYPRO protein gel stain photographic filter (S-6656) is recommended