Fluorescent Nanoparticles Identify Bacteria

Scientists at the University of Florida have designed tiny fluorescent particles that can be used to rapidly identify bacteria by color coding them. This could be useful for preventing bioterror attacks, rapidly diagnosing infections, and testing food for contaminants.

Current technology, including the infamous Gram Stain, can only divide bacteria into two broad categories. The new method can determine the exact species and sort various types of bacteria on the same microscope slide.

Professor Weihong Tan and his students created nanoparticles with three different colors, blue for Escherichia coli, orange for Stapphylococcus aureus, and purple for Samonella typhimurium. They attached different antibodies to each of the colored nanoparticles.

Antibodies are proteins that stick to one and only one thing. In this case, each nanoparticle contained antibodies that would latch onto a single type of bacteria.

When they put all three particles into a broth with three different types of bacteria, the nanoparticles color coded those bacteria so that they could be very quickly identified by looking at them through a confocal microscope. Tan and his team reported their findings in the current issue of Bioconjugate Chemistry, a journal that deals with attaching biological molecules like antibodies to other molecules, surfaces, and nanoparticles.

Aby.T.Joseph

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