Science News-The Gibson Assembly

In the last couple of years scientists have begun to use a powerful new method of making DNA sequences, even quicker and more efficiently then by polymerase chain reaction. The method was developed at the J. Craig Venter Institute, and allows 2 or more single or double stranded DNA segments to be rapidly joined in a matter of minutes. Basically the two segments to be joined must have the potential to overlap by 20 or more bases. The overlapping DNAs, and there may be 10 or more of them, are treated with a mixture of a ligase, a nuclease and a polymerase. The nuclease, if required, generates potential regions of overhang from double stranded DNAs, allowing two DNAs to anneal. Following annealing, the polymerase fills in any gaps in the overhangs and ligase completes the reaction by joining 5' and 3' ends. The method does not require the insertion of restriction sites or the use of PCR which can introduce errors at a significantly higher rate. The method was used to generate an entire mouse mitochondrial genome and also the artificial genome of Hemophilus venteri, arguably the first synthetic organism. We were fascinated by this and so of course had to try it- it worked! So we generated an on line program for anyone who would like to generate long DNA sequences from overlapping 60 base segments as described by this group.