Please see the following link describing our LPS products: https://www.sigmaaldrich.com/technical-documents/protocol/clinical-testing-and-diagnostics-manufacturing/bacteriology/lipopolysaccharides
Solutions at 1 mg/mL in buffer or culture medium are stable for approximately one month at 2-8 °C. For long term storage, frozen aliquots are stable up to 2 years. Avoid repeated freeze/thaw cycles. Solutions should be stored in silanized containers as LPS can bind to plastics and certain types of glass, particularly at concentrations of <0.1 mg/mL. If the LPS concentration is >1 mg/mL, adsorption to the sides of the vial is negligible. If glass containers are used, solutions should be vortexed for at least 30 minutes to redissolve any adsorbed product.