FIG. 4.
Northern blot of RNA isolated from S. mitis strains and hybridized with a pblB probe. Lanes: 1, RNA from the parental strain SF100; 2, RNA from the pblA mutant strain PS301. Arrows indicate the predominant prgB transcripts. The bands seen at 2.5 kb correspond to nonspecific hybridization to the 23S rRNA.