Running Buffer for Small Proteins
Variation on the Schagger/von Jagow System
Substitute for Tris-Glycine-SDS in the Standard Laemmli Protocol
Discontinuous SDS-PAGE employing Tris-Glycine as the tank buffer resolves proteins down to about 15 kd. However, below this size, the proteins do not destack from the SDS micelles running through the gel with the buffer front. In order to resolve proteins in this size range, the Tris-Tricine system of Schagger and von Jagow (1987) was developed.
An Alternative to the Schagger and von Jagow System involves running Tris-Tricine Gels using National Diagnostics 10X Tris-Tricine-SDS Buffer (EC-869). With National Diagnostics Tris-Tricine-SDS, you can extend the range of SDS-PAGE to resolve smaller proteins with minimal alteration of protocol.
To provide this level of convenience, National Diagnostics streamlined the original method of Shaggar and Von Jagow (1987 Anal. Biochem 166) by developing Tris-Tricine-SDS cathode tank buffer to be compatible with the standard Laemmli gel/buffer system. This combination resolves proteins as small as 5kD. The researcher simply substitutes National Diagnostics Tris-Tricine-SDS in the upper (cathode) tank, with no other changes from standard Laemmli protocol to extend the resolution of their gels.