Why use bam h1 ans sau3a1 in plasmid transformation?

Answer 1

Because they share compatible sites. Whatever you digest with Sau3A1, you can ligate it in a BamHI site.

Answer 2

BamHI and Sau3A1 are restriction enzymes that can be used to linearize or digest plasmid DNA during the transformation process. Linearizing the plasmid with these enzymes makes it easier for the foreign DNA to be inserted and integrated into the plasmid. This helps in efficiently producing recombinant plasmids with the desired DNA insert.