Working with Plasmids
Endotoxins and what to consider
What are endotoxins?
Endotoxin contamination of different plasmid preparation methods
How are endotoxins measured?
Influence of endotoxins on biological applications
Endotoxin-free plasticware and glassware
To avoid recontamination of plasmid DNA after initial endotoxin removal, we recommend using only new plasticware which is certified to be pyrogen- or endotoxin-free. Endotoxin-free or pyrogen-free plasticware can be obtained from many different suppliers.
Endotoxins adhere strongly to glassware and are difficult to remove completely during washing. Standard laboratory autoclaving procedures have little or no effect on endotoxin levels. Moreover, if the autoclave has previously been used for bacteria, the glassware will become extensively contaminated with endotoxin molecules. Heating glassware at 180°C overnight is recommended to destroy any attached endotoxin molecules.
It is also important not to recontaminate the purified endotoxin-free DNA by using reagents that are not endotoxin-free.