Automatically count colonies with the click of a button. Users can easily process time-lapse counting, zone sizing, and spiral counting. The system illuminates colony plates with multiple excitation sources to visualize white light and fluorescent colonies including GFP colonies. The high-resolution digital color camera identifies the smallest colonies. Plate and filter sizes from 33-150mm can be accommodated. Doors create a darkroom environment, eliminating ambient light. Applications include food and beverage control, microbiology, hygiene studies, antibiotic testing, quality control, and fluid contamination. Colony Counting GFP Bacteria An example of colony counting is demonstrated in Analytik Jena's Applications Note FP-142 discusses illumination and counting of GFP expressing E.Coli colonies. Originally extracted from jellyfish, GFP (Green Fluorescent Protein) is a fluorescent protein that emits a green glow. GFP absorbs the energy of blue light and then emits the partially-consumed energy as a green light. GFP is employed as an easily detectable marker. When a bacterial colony is labeled with GFP for comparative study, incubated under protocol conditions, and viewed under blue light, the GFP bacteria emits green light. The green light emission allows the researcher to visualize and distinguish the GFP-labeled bacteria, which makes the distinction of GFP-labeled cells from unlabeled cells simple and effective. The UVP ColonyDoc-It is configured with an epi blue light (~470nm) excitation source. A GFP filter is added to optimize the enumeration of colony growth of bacterial and yeasts labeled with GFP. The ColonyDoc-It Imaging Station provides a simple instrument for capturing, counting, and reporting GFP-labeled colonies. By providing researchers with built-in epi blue lighting for fluorescence along with an optimized GFP filter, colonies are detectable and counted with ease and accuracy.