# FAQ: Why did you remove DTT from your restriction enzyme buffers?

DTT was originally included in the buffer formulation for historical reasons. That is, DTT is commonly used is many molecular biology enzyme buffers and thus was also included in these restriction enzyme buffers, when they were first developed. However, after extensive testing, we have found that it is not necessary for restriction enzyme activity.  In addition, BSA in the presence of DTT can on occasions form a white precipitate after repeated freeze/thaws.