This work was supported by grants from the National Institutes of Health and the Cystic Fibrosis Foundation.

1. Preparation of Bacteria for LPS Extraction
<ol>
	<li>Start an overnight culture in 5 mL of Luria Broth (LB), supplemented with antibiotics if necessary. Grow culture overnight (12-18 hours) in a shaking incubator at 37 &deg;C and 200 rpm.</li>
	<li>Dilute the culture 1:10 with LB and take an OD600 reading in a spectrophotometer. Based on the OD600 reading, make a 1.5 mL suspension of your bacteria to an OD600 of 0.5.</li>
	<li>Pellet the bacteria in a microcentrifuge at 10,600x g...

<ol>
	<li>Raetz, C. R., Whitfield, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipopolysaccharide+endotoxins.">Lipopolysaccharide endotoxins.</a> Annu. Rev. Biochem. 71, 635-700 (2002).</li><li>Valvano, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Export+of+O-specific+lipopolysaccharide.">Export of O-specific lipopolysaccharide.</a> Front. Biosci. 8, 452-471 (2003).</li><li>Pier, G. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pseudomonas+aeruginosa+lipopolysaccharide:+a+major+virulence+factor,+initiator+of+inflammation+and+target+for+effective+immunity.">Pseudomonas aeruginosa lipopolysaccharide: a major virulence factor, initiator of inflammation and target for effective immunity.</a> Int. J. Med. Microbiol. 297, 277-295 (2007).</li><li>Freudenberg, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+lipopolysaccharide+susceptibility+in+the+innate+immune+response+to+Salmonella+typhimurium+infection:+LPS,+a+primary+target+for+recognition+of+Gram-negative+bacteria.">Role of lipopolysaccharide susceptibility in the innate immune response to Salmonella typhimurium infection: LPS, a primary target for recognition of Gram-negative bacteria.</a> Microbes Infect. 3, 1213-1222 (2001).</li><li>Jann, K., Jann, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polysaccharide+antigens+of+Escherichia+coli.">Polysaccharide antigens of Escherichia coli.</a> Rev. Infect. Dis. 9, S517-S526 (1987).</li><li>McCallum, K. L., Schoenhals, G., Laakso, D., Clarke, B., Whitfield, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+high-molecular-weight+fraction+of+smooth+lipopolysaccharide+in+Klebsiella+serotype+O1:K20+contains+a+unique+O-antigen+epitope+and+determines+resistance+to+nonspecific+serum+killing.">A high-molecular-weight fraction of smooth lipopolysaccharide in Klebsiella serotype O1:K20 contains a unique O-antigen epitope and determines resistance to nonspecific serum killing.</a> Infect. Immun. 57, 3816-3822 (1989).</li><li>Hancock, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pseudomonas+aeruginosa+isolates+from+patients+with+cystic+fibrosis:+a+class+of+serum-sensitive,+nontypable+strains+deficient+in+lipopolysaccharide+O+side+chains.">Pseudomonas aeruginosa isolates from patients with cystic fibrosis: a class of serum-sensitive, nontypable strains deficient in lipopolysaccharide O side chains.</a> Infect. Immun. 42, 170-177 (1983).</li><li>Gupta, S. K., Masinick, S., Garrett, M., Hazlett, L. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pseudomonas+aeruginosa+lipopolysaccharide+binds+galectin-3+and+other+human+corneal+epithelial+proteins.">Pseudomonas aeruginosa lipopolysaccharide binds galectin-3 and other human corneal epithelial proteins.</a> Infect. Immun. 65, 2747-2753 (1997).</li><li>Hitchcock, P. J., Brown, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphological+heterogeneity+among+Salmonella+lipopolysaccharide+chemotypes+in+silver-stained+polyacrylamide+gels.">Morphological heterogeneity among Salmonella lipopolysaccharide chemotypes in silver-stained polyacrylamide gels.</a> J. Bacteriol. 154, 269-277 (1983).</li><li>Westphal, O., Jann, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bacterial+lipopolysaccharides.">Bacterial lipopolysaccharides.</a> Methods Carbohyr. Chem. 5, 83 (1965).</li><li>Lieberman, T. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Parallel+bacterial+evolution+within+multiple+patients+ties+novel+genes+to+pathogenesis.">Parallel bacterial evolution within multiple patients ties novel genes to pathogenesis.</a> Nat Genet. , (2011).</li></ol>

No conflicts of interest declared.

We have described a method of purifying LPS away from other cellular components, including nucleic acids and proteins. This method provides high-quality LPS that can be used in a number of different visualization methods, including carbohydrate staining of SDS-PAGE gels, as shown in Figure 1. This method can be used to serotype LPS from a variety of strains, using specific anti-sera, or to show relatedness between isolates by direct visualization. For example, a recent genome-wide sequencing project in combinatio...

<table border="1">
<tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 </tr>
 <tr>
 <td>DNase I recombinant, RNase-free</td>
 <td>Roche</td>
 <td>04716728001</td>
 </tr>
 <tr>
 <td>RNase A</td>
 <td>Roche</td>
 <td>10109169001</td>
 </tr>
 <tr>
 <td>Proteinase K</td>
 <td>Fisher</td>
 <td>BP1700</td>
 </tr>
 <tr>
 <td>Tris-Saturated Phenol</td>
 <td>Fisher</td>
 <td>BP1750-100</td>
 </tr>
 <tr>
 <td>Diethyl Ether</td>
 <td>Thomas Scientific</td>
 <td>C313K31</td>
 </tr>
 <tr>
 <td>Pro-Q Emerald 300 Lipopolysaccharide Gel Stain Kit </td>
 <td>Molecular Probes</td>
 <td>P20495</td>
 </tr>
 </tbody>
</table>

purification and visualization of lipopolysaccharide from gram-negative bacteria by hot aqueous-phenol extraction

Lipopolysaccharide (LPS) is a major component of Gram-negative bacterial outer membranes. It is a tripartite molecule consisting of lipid A, which is embedded in the outer membrane, a core oligosaccharide and repeating O-antigen units that extend outward from the surface of the cell1, 2. LPS is an immunodominant molecule that is important for the virulence and pathogenesis of many bacterial species, including Pseudomonas aeruginosa, Salmonella species, and Escherichia coli3-5, and differences in LPS O-antigen composition form the basis for serotyping of strains. LPS is involved in attachment to host cells at the initiation of infection and provides protection from complement-mediated killing; strains that lack LPS can be attenuated for virulence6-8. For these reasons, it is important to visualize LPS, particularly from clinical isolates. Visualizing LPS banding patterns and recognition by specific antibodies can be useful tools to identify strain lineages and to characterize various mutants. 
In this report, we describe a hot aqueous-phenol method for the isolation and purification of LPS from Gram-negative bacterial cells. This protocol allows for the extraction of LPS away from nucleic acids and proteins that can interfere with visualization of LPS that occurs with shorter, less intensive extraction methods9. LPS prepared this way can be separated by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) and directly stained using carbohydrate/glycoprotein stains or standard silver staining methods. Many anti-sera to LPS contain antibodies that cross-react with outer membrane proteins or other antigenic targets that can hinder reactivity observed following Western immunoblot of SDS-PAGE-separated crude cell lysates. Protease treatment of crude cell lysates alone is not always an effective way of removing this background using this or other visualization methods. Further, extensive protease treatment in an attempt to remove this background can lead to poor quality LPS that is not well resolved by any of the aforementioned methods. For these reasons, we believe that the following protocol, adapted from Westpahl and Jann10, is ideal for LPS extraction.

Watch this Scientific Journal Video about Purification and Visualization of Lipopolysaccharide from Gram-negative Bacteria by Hot Aqueous-phenol Extraction at JoVE.com

Purification and Visualization of Lipopolysaccharide from Gram-negative Bacteria by Hot Aqueous-phenol Extraction

We describe a modified hot aqueous-phenol extraction method for purifying lipopolysaccharide (LPS) from Gram-negative bacteria. Once extracted, the LPS can be subsequently analyzed by SDS-PAGE and visualized by direct staining or Western immunoblot.

Lipopolysaccharide (LPS)  is a major component of Gram-negative bacterial outer membranes. It is a tripartite molecule consisting of  lipid A, which is ...

purification-visualization-lipopolysaccharide-from-gram-negative

Research

JoVE Journal

Immunology and Infection

34.6K Görüntüleme.  University of Virginia Health System. Biz Gram-negatif bakterilerden lipopolisakkarid (LPS) arıtılması için modifiye edilmiş bir sıcak sulu-fenol ekstraksiyon yöntemi açıklar. Bir kez çıkarılan, LPS sonradan SDS-PAGE ile analiz ve direkt boyama ya da Batı immunoblotting tarafından görüntülenebilir.