Isolation of <i>T.b. brucei</i> clones expressing high level bioluminescence.

<p>(<b>A</b>) The bioluminescent signal (RLU) detected from <i>T.b. brucei</i> s427 clones transfected with pTb-AMluc constructs in which the <i>PpyRE9H</i> gene was flanked by 5′-<i>VSG</i> and 3′-<i>tubulin</i>, <i>5′-GPEET2 procyclin</i> and 3′-<i>tubulin</i>, or 5′-<i>GPEET2 procyclin</i> and 3′-<i>actin</i> UTRs (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002571#pntd-0002571-g001" target="_blank">Figure 1</a>). Luciferase assays were carried out on 10⁶ cells (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002571#s2" target="_blank">Materials and Methods</a>), with readings taken using a SpectraMax M3 Microplate Reader. The data show that the 5′-<i>VSG</i>/3′-<i>tubulin</i> UTR combination in construct pTb-AMluc-v gives the highest luciferase signal <i>in vitro</i>. Clones 1–4 (indicated) were used in assessment of growth (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002571#pntd.0002571.s001" target="_blank">Figure S1</a>). (<b>B</b>) The bioluminescent signal detected from <i>T.b. brucei</i> GVR35 clones transfected with construct pTb-AMluc-v. Clone VSL2 (indicated) was chosen for <i>in vivo</i> studies.