Sigma Buffer for Capillary Electrophoresis (B-4930) is much chaper than ABI buffer. To date I have no problem using the Sigma buffer for sequencin run. It is convenient also, because it can be stored at room temperature, but be careful to avoid salt precipitation around the bottle cap. In my experience, however, the Sigma buffer did not work for 4-color fragmant analysis run, but I have heard in another lab it works fine for the fragment analysis run. I do not know this difference is of the buffer lot specific or machine specific. I have not yet tested a buffer supplied by Gel Company.