( Endotoxin Testing Endotoxin levels...)Introducing,,,GenElute HP,,,Endotoxin-Free Plasmid,,,Maxiprep Kit

Results and Discussion
The GenElute HP Endotoxin-Free Maxiprep Kit was compared to three other commercially available kits by purifying pCMV-SPORT-β-gal from the same bacterial culture. The first was the Sigma GenElute HP Maxiprep Kit, the second was an endotoxin-free kit that utilizes anion-exchange gravity-flow columns, and the third was an endotoxin-reducing silicabased kit that incorporates magnetic particles into the purification process. In addition, plasmid pCMV-SPORT-β-gal was prepared from a separate culture on two cesium chloride gradients (2X CsCl banding).

Plasmid recoveries, endotoxin levels, and time/prep for all the samples were compared in Table 1. Plasmid yields obtained from the GenElute HP Endotoxin-Free Plasmid Maxiprep Kit were similar to or better than the other methods. Endotoxin levels were also among the lowest when compared to the other available endotoxin-free kits, the Sigma GenElute HP Maxiprep Kit as well as the 2X cesium chloride sample. The most significant difference between the endotoxin-free kits was in the time/prep. The GenElute HP Endotoxin-Free Plasmid Maxiprep Kit took only 35 minutes to complete, while two other competing endotoxin-free kits took over four times as long. Only the GenElute HP Maxiprep Kit was comparable in preparation time, but the purified sample had higher levels of endotoxin.

Table 1. Comparison of plasmid yield, endotoxin levels and time/prep for the different purification systems for pCMV-SPORT-β-gal.

Purification System Plasmid Yield (mg) Endotoxin Levels (EU/g) Time/Prep (minutes) GenElute HP Endotoxin-Free Maxiprep Kit 1.4 0.02 35 GenElute HP Maxiprep Kit 1.6 7
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