ABSTRACT

Purified LPS is traditionally visualized by silver staining after SDS-PAGE or DOCPAGE1 analysis (Figure 1), which reveals that bacteria express a heterogeneous population of LPS molecules with a Mr range of ~2000 to 50000. This is because some LPS molecules do not carry any O-specific polysaccharide chains at all (Mr~2000), while those that do vary greatly in the length of the individual polysaccharide chains (Mr>2000 to 50000). (For recent reviews on LPS biosynthesis see (Raetz and Whitfield, 2002; Whitfield and Valvano, 1993).