STRU-cloning: a fast, inexpensive and efficient cloning procedure applicable to both small scale and structural genomics size cloning.

We have developed a Single-Tube Restriction-based Ultrafiltration (STRU) cloning procedure that updates traditional ligation-dependent cloning to challenge the newer, faster and more efficient ligation-free techniques and could make it the method of choice. STRU-cloning employs centrifugal filter units with membrane of suitable cut off to remove small unwanted DNA fragments created during restriction of plasmids or PCR products. Heat inactivation, of restriction enzymes, followed by DNA ligation is then performed on the filtrate. By removing the agarose gel electrophoresis DNA purification step from the traditional protocol, which is time consuming and is known to be the cause of ligation problems, STRU-cloning becomes fast, very efficient, inexpensive and offers the highest degree of cloning flexibility by using restriction sites and can be performed in a single tube. This novel agarose gel-free cloning procedure provides benefits for both small and large scale cloning projects. Unlike traditional cloning it can be easily implemented as a fully automated process at very low costs.