Does culture passaging or media change reduce endotoxin levels?
This depends on the type of cells and nutrients / media type, also how frequent you change this media.
Lipopolysaccharides (also called endotoxins) are elements of the cell wall of Gram-negative bacteria. There are two basic ways of appearance of the endotoxin in the medium. Firstly, contamination of the sterile culture medium. Secondly, experiments with primary culture of living cells, which are always present in bacteria. Consequently, it is first necessary to observe the rules of asepsis and antisepsis. It is necessary to use antibiotics. Changing the culture medium is one of the favorable factors. But the effect of this factor compared to the previous two is minimal.
Another way to introduce endotoxin in your culture medium is transfection using DNA prep no endotoxin free. For the rest, the answer of Vladimir is correct. But I have a question: are you talking about real endotoxin (ie LPS) or do you mean "toxins" naturally produced by cell's metabolism?
yes, if you change the medium ist will "go awy" but check for contamination with bacteria
during passage 1 of Mesenchymal Stromal Cell culture the endotoxin level when checked with ENDOSAFE PTS was
It depends. Necessary to check one more time. Why? Please, see my previous answer...
Generally, when normal cells are infected/contaminated with microorganisms ( bacteria /mycoplasma) they may be the source of endotoxin. Cancer cells may be the source of some level of toxins. Normal Human or mammalian cells may not be the source of endotoxins. Passaging of cells definitely changes the cells and therefore reduce toxins. This is the way attenuated vaccines are prepared. Similarly media changes also may reduce toxin levels.
Please give information about cell type, medium and frequency of passaging. If possible type of endotoxin.
I assume that the safe (minimum) EU level will always be there no matter how many times u change your media or even follow strict aseptic techniques .. Theoretically this level cannot be zero....
Dear colleagues. We're talking about the consequences of contamination and endotoxemia. But the reason for the appearance of the endotoxin in the culture medium due to the decay of bacteria (mainly Gram-negative). Endotoxin activates TLR4 complex and CD14. Activation of complex accompanied by an increase of cytokines in the culture medium, primarily inflammatory (IL6, TNF, IL1beta. The consequence of these processes is the change of proliferation, apoptosis. What if a scientist would study? The action of endotoxin or other problems? Or action of factors, including endotoxins? Thus, in the first place to avoid contamination.
the only reason you would see endotoxin in your cultured cells is if the media used is contaminated,just check your media preparation well and probably the incubator for any hazardous contaminants.
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