An enhancer trap is a method in molecular biology. The enhancer trap construct contains a transposable element and a reporter gene. The first is necessary for (random) insertion in the genome, the latter is necessary for identification of the spatial regulation by the enhancer. On top of this, the construct usually includes a genetic marker, e.g., the mini-white gene, which restores red eye color in Drosophila, or ampicillin resistance in E. coli.