( vectors arelarge to begin with ma...)New Competent Cells for Highest Transformation Efficiencies

vectors, are large to begin with, making this size bias more acute. Plasmid cDNA libraries constructed in current E. coli hosts have limited numbers of primary isolates and do not accurately reflect the cDNAs that are present.

Stratagene has endeavored to maximize the size of plasmid libraries and minimize the size bias when constructing plasmid libraries by improving the efficiency with which ligated DNA can transform E. coli. These efforts have resulted in the creation of XL10-Gold ultracompetent cells, a new E. coli host that exhibits notably higher transformation efficiency for ligated DNA molecules. The ability to better accept ligated, or larger, DNA molecules means that a plasmid library constructed in XL10-Gold cells will more faithfully represent the population of cDNA molecules.

Transformation of a Large Supercoiled Plasmid