Lipopolysaccharides (LPS), often referred to as endotoxins, are produced by gram-negative bacteria such as E. coli and detected by the immune system of eukaryotic organisms. This can trigger an immune response and result in reduction of gene expression. In kit preparations, LPS content may vary very widely and have undesirable effects on the results of the experiment. During each plasmid production, PlasmidFactory measures the LPS content and can guarantee, upon request, a client specific content. Thus, the levels undermatch those of all other manufacturing processes.