<i>Gaussia</i> luciferase is secreted from mycobacterial cells.

<p>Luminescence (given as relative light units [RLUs]) was measured in culture, supernatant and cell samples of <i>M. smegmatis</i> producing Gluc <i>Mycobacterium</i> optimised with (GlucSS) or without (Gluc) signal peptide, Gluc wild-type with (GlucWT+SS) or without (GlucWT-SS) signal peptide, and FFluc as control. Assays were performed with three independent cultures and each culture was measured in duplicate. As the data was not normally distributed, median values are displayed (bar) with inter-quartile ranges (box), and highest and lowest values (whiskers).