PureLink Expi kits provide endotoxin-free plasmid DNA in about half the time

Invitrogen PureLink Expi Endotoxin-Free Plasmid Purification Kits use a novel, proprietary anion-exchange resin to isolate advanced transfection–grade plasmid DNA in about half the time of current standard protocols. The enhanced resin in combination with the vacuum-assisted workflow dramatically reduces purification time to less than 2 hours. The quick and simple protocol is designed to provide up to 1.5 mg (maxiprep), 5 mg (megaprep), or up to 15 mg (gigaprep) of high-quality endotoxin-free plasmid DNA suitable for advanced transfection applications such as transfection of sensitive cells lines or in vivo experiments. The PureLink Expi Endotoxin-Free kits are compatible with the Gibco ExpiCHO and Expi293 transient mammalian expression systems.

Features of the PureLink Expi Endotoxin-Free Plasmid
Purification kits

  • Substantial time savings—no waiting for gravity-flow columns; purify endotoxin-free plasmid DNA in as little as 90 min (maxiprep) and 2 hr (megaprep and gigaprep)
  • High yields—isolate up to 1.5 mg (maxiprep), 5 mg (megaprep) or 15 mg (gigaprep) of high-quality plasmid DNA
  • Endotoxin-free DNA—obtain plasmid with less than 0.1 EU/µg, ideal for sensitive applications such as transfection of primary cells and research on gene therapy or plasmid vaccines

Example data

Figure 1. Achieve high yields of endotoxin-free, advanced transfection–quality plasmid DNA with PureLink Expi when compared to kits from a competitor. Two high-copy plasmids with different backbones were purified using PureLink Expi and Qiagen EndoFree maxiprep, megaprep, and gigaprep kits as described in the product manuals. Data for DNA yields are shown in the graph; endotoxin values (EU/μg) are provided only for PureLink Expi preps.


Figure 2. Rapidly purify high yields of endotoxin-free plasmid DNA. PureLink Expi kits enable high yields of endotoxin-free, advanced transfection–grade plasmid DNA in less time than Qiagen EndoFree kits. The combination of advanced anion-exchange technology and vacuum assistance reduces overall protocol time compared to Qiagen EndoFree gravity-flow kits.


Figure 3. Plasmid DNA ideal for transfection in sensitive cell lines. The hepatic cell line Huh7 is known to be very sensitive to endotoxin levels during transfection. Luciferase activity was measured from Huh7 cells transfected with a luciferase expression plasmid purified using the PureLink Expi system or the Qiagen EndoFree system.


Figure 4. Plasmid DNA purified with PureLink Expi kits is compatible with the Gibco Expi293 and ExpiCHO Expression Systems. Using the Expi293 and ExpiCHO Expression Systems, cells were transfected with positive controls of rabbit IgG heavy chain and light chain plasmids that were purified using the PureLink Expi megaprep kit or the Qiagen EndoFree mega prep kit. The above titer values fall within the expected outputs of the Expi Expression Systems.