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| Endotoxins, transfection and JETSTAR Plasmid Purification Kits |
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Since transfection became an important tool to investigate gene expression
and regulation, several methods of gene transfer into eukaryotic cells were
developed (liposomes, electroporation, calcium phosphate etc.).
However, transfection efficiencies using these methods vary widely between cell types, cell lines and plasmids. Moreover, even when the same basic conditions (same transfection method, same cell line, same type of plasmid) are used, transfection efficiencies can vary between all and nothing, when the used plasmid DNA is prepared by different methods. The most significant difference between differently purified DNAs can be found in their contamination with endotoxins. When endotoxins (LPS) are determined by tests like the BIOWHITTAKER QCL-1000, the outcome is measured in EU (endotoxin units) per microgram plasmid DNA. Achieve transfection-grade plasmid purity with GENOMEDs new NoEndo JETSTAR ENDOTOXIN-FREE Plasmid Purification Kits to provide truly endotoxin-free plasmid DNA or GENOMEDs established JETSTAR/LFU or JETSTAR Plasmid Purification systems, made for the preparation of plasmid DNA with very low endotoxin contents. This patented anion-exchange technology purifies high- and low-copy number plasmids with endotoxin contents being as low as 10-3 EU per microgram DNA with the new NoEndo JETSTAR ENDOTOXIN-FREE Plasmid Kits. This is a significantly better DNA quality than DNA passed through two rounds of CsCl gradient centrifugation. Transfection efficiencies using JETSTAR-purified plasmid DNA were examined for a large number of eucaryotic cell types. Two examples (see figures below) illustrate... |
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| Effect of DNA preparation on transfection.
Purified plasmid DNA was transfected into K562 cells and Huh7 cells.
K562 cells: DNA after alkaline lysis (A), DNA after 2xCsCl, but 25000 EU added (C1), 2xCsCl (C2), JETSTAR purified DNA (J). Huh7 cells: DNA after alkaline lysis (A), Endotoxin-free DNA, but 40 EU added (Q1) and Endotoxin-free DNA from supplier Q (Q2). |
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