Description Catalog number: EC-8740.2 micron filtration18 MegOhm waterThe SDS used in National Diagnostics’ 20% SDS Solution has been purified to remove colored contaminants that interfere with spectrophotometric analysis. Zero-free sulfates eliminate non-specific binding.Molecular WeightPurityOD280(3M solution)288.38> 99%< 0.1C12SulfateLead (Pb)Phosphate (PO4)≥ 99%< 0.0002%< 0.0001%