استخراج ليپوپلي ساكاريد خالص از لايه خارجي ديواره سالمونلاتيفي

Purification of Lipopolysaccharides from Salmonella `phimurium PTCC 1735

Lipopolysaccharide (LPS) is one of the most important components of Gram negative bacteria cell walls which form a hydrophobic unit (Lipid A) and a hydrophilic unit (polyssaccharide). Extraction and purification of LPS is an essential step in determination of biochemical, pathophysiological and immunological properties. In the present report the LPS of Salmonella typhimurium PTCC 1735 was extracted and purified. The phenol-water solution method was used to extract the bacterial LPS. Proteins and nucleic acids were removed by means of pronase and nucleases and gel filteration. Crude LPS yield was about 1.8% of initial bacterial dry weight. After gel filteration the content of protein and nucleic acids in LPS preparations were calculated to he 0.2% and 0.5% respectively. Profiles of pure LPS by SDS_PAGE were demonstrated.