Large-scale preparations of plasmid DNA encoding cytokine cassettes are
continuously gaining in importance in many areas of gene-therapy (1) including
DNA vaccinations with plasmid cytokine adjuvants (2–4), tumor research
(5), and treatment of infectious diseases (6,7). Small-scale plasmid preparations
(approx 10–100 µg DNA) usually result in adequate yields, whereas largescale
(>1 mg DNA) preparations of plasmid DNA can result in
disproportionally small yields of DNA. We have found that using Terrific broth
(TB) rather than Luria-Bertani (LB) broth in available kits significantly (approx
fivefold) increases plasmid DNA yields (see Note 1). This suggestion is especially
true for low or very low copy plasmids. In this chapter, we give an overview
of different plasmid purification techniques commonly used, and describe
advantages and disadvantages for each method