Compact Filter-Based Fluorescence Microscope for Rapid Legionella Detection

Rapid detection of Legionella pneumophila (LP) from air conditioning units, cooling towers, fountains or mist generators demands that microscopy be used to actually see the small numbers of bacterial cells concentrated on a filter membrane from a 100 ml or greater volume water sample. Filtration can be achieved by suction or positive pressure with a syringe .Nanohmics will develop a membrane filtration system similar to the older Direct Epifluorescence Filter Technique (DEFT) test with a compact or cell phone-based automated scanning microscope and the ability to zoom in on speckled fluorescent regions of interest to see the fluorescently labeled bacterial pathogens and accelerate filter scanning. Acridine orange or other fluorescence viability stains will also be employed to determine if captured bacteria are alive. The portable fluorescence microscopy system will be an improvement over DEFT by using high affinity and highly specific anti-LP and LP serogroup 1 antibody-quantum dots (Qdots) making regions of interest fluoresce brighter with bound Qdots. In Phase II, Nanohmics will design and build a prototype compact scanning fluorescence microscope or cell phone microscopy attachment for reading the stained filters in the field.