Endotoxin is the lipopolysaccharide (LPS) complex located in the outer membrane of gram-negative bacteria. During experimental procedures, large amount of endotoxins are shed and can easily contaminate labware, buffers and downstream products. Presence of endotoxin in any of these has a detrimental effect on culturing of cells and can lead to generation of irreproducible or negative experimental data. Therefore, it is critical to keep endotoxin away from samples and products. ToxOut? Endotoxin-free Water is recommended to use for samples with special requirement of endotoxin level (< 0.05 EU/ml).