Buffers must be refrigerated when not in use to prevent microbial growth and contamination. Using a buffer at refrigerator temperature also improves band resolution and lessens evaporation during electrophoresis.
For electrophoresis, it is recommended to use a small volume of buffer and a fresh buffer for each run. After a large-volume buffer electrophoresis, the buffer can be reused if the buffer from each reservoir is combined, mixed well, and refrigerated.
