New plasmids for <i>S. pneumoniae</i> cell biology studies.

<p>(A) Map of the pBCS plasmids. Fluorescent protein refers to mCherry, Citrine, CFP or GFP, encoded by plasmids pBCSMH030, pBCSJC001, pBCSMH031 and pBCSMH032, respectively. <i>Apa</i>I and <i>Nae</i>I restriction sites, highlighted with an asterisk, are not available in plasmid pBCSMH030. <i>repA, repB</i>, plasmid replication genes. <i>tet</i>, tetracycline resistance marker. T, transcription terminator. P, promoter. S₁, stop codon in plasmid pBCSMH030. S₂, stop codon in plasmids pBCSJC001, pBCSMH031 and pBCSMH032. (B) Comparison of fluorescence emitted by strains expressing mCherry, Citrine, CFP and GFP alone, their improved i-tag versions and their Wze fusions. The median fluorescence, with 25% (white error bars) and 75% (black error bars) inter-quartile range (in arbitrary units) is plotted. At least 100 cells of each strain were quantified. Strain names are indicated below.