4X Protein Sample Loading Buffer is optimized for use as a loading buffer for protein gel electrophoresis. This orange loading buffer is recommended for use with Odyssey® Imaging Systems as it does not fluoresce in the 700 nm channel the way blue loading buffers do. The buffer is optimized for use with SDS-PAGE and Tris-Glycine-SDS running buffer, as well as Bis-Tris protein gels and MES SDS running buffer.