Detection of GFP induction early in the developmental cycle.

<p>L929 cell cultures infected with transformed <i>C</i>. <i>trachomatis</i> were induced at the start of infection (0 hpi). Samples were taken and lysates prepared at the indicated time points after the start of infection. GFP fluorescence was measured using a microplate fluorometer with the results quantified in arbitrary units. Error bars indicate standard deviation from two separate experiments.