FIG. 1.

Southern hybridization map of the N. meningitidis B16B6 lbpA upstream region and diagrammatic representation of ligation-based PCR protocol. A genetic map of the regions immediately upstream of the N. meningitidis B16B6 lbpA gene (lbpA start is indicated) was determined by Southern hybridization analysis using an lbpB-specific DNA probe (36). Ligation-based PCR was used to amplify the region upstream of lbpA. Depicted is a single-step ligation-based PCR protocol in which the chromosomal DNA from N. meningitidis B16B6 was digested with XbaI (XbaI site situated approximately 2.6 kb upstream of lbpA start) and ligated to XbaI-linearized pT7 vector. The ligated fragments were used as templates in a PCR using the T7 primer and an lbpA-specific primer. Scale is in base pairs.