A method for using cloning vector plasmids to produce DNA molecules, such as transgenes, in a single cloning step. The transgenes can be used for the purpose of gene expression or analysis of gene expression. The plasmid cloning vectors are engineered to minimize the amount of manipulation of DNA fragment components by the end user of the vectors and the methods for their use. Transgenes produced using the invention may be used in a single organism, or in a variety of organisms including bacteria, yeast, mice, and other eukaryotes with little or no further modification.