FIG. 5.

PCR-hybridization analysis of lpsB-homologous sequences in various bacteria. (A) A PCR assay was carried out with primers LPSB2F and LPSB2R, designed according to the sequence conservation between S. meliloti lpsB and the homologous lpcC of R. leguminosarum bv. viciae. PCR products were separated on 2% (wt/vol) agarose gels containing 0.5 to 1 μg of ethidium bromide per ml and photographed with a Kodak DC120 digital camera under UV illumination. Strains are indicated above the lanes. MWM, molecular weight marker (lambda phage DNA digested with HindIII). (B) The PCR products from panel A were analyzed by Southern blot hybridization using a 532-bp digoxigenin-labeled DNA probe which is internal to lpsB and contains the amplified region.