Lipopolysaccharide neutral solution can be stored at room temperature for several months, and its biological activity does not change significantly. If it is stored at 4 ℃ or in a low-temperature refrigerator, its biological activity can remain unchanged for several years to decades. Dry lipopolysaccharide neutral powder can be stored at room temperature or refrigerator for decades or longer without losing its biological activity.
When lipopolysaccharide is placed in an acidic solution at room temperature, its molecules undergo partial degradation. This change mainly involves the cleavage of glycosidic bonds between polysaccharide and lipid A, and the cleavage of lipid A1-glucoside bonds. Heating can promote this reaction. A strong acid solution can completely destroy lipopolysaccharide under heating conditions.
Alkaline factors have a great influence on lipopolysaccharide molecules, mainly on lipid A molecules. At this time, the 4-phosphate ester bond on the lipid A skeleton and the fatty acid ester bond on the 3 and 3 positions are easy to be destroyed, which can cause the molecule to split. At this time, the degraded molecules lose their typical endotoxin activity. Lipopolysaccharides can be completely destroyed under strong alkali conditions.