In the computer displays of medical equipment in hospitals and clinics, liquid crystal technologies have already found a major role. But a discovery reported from the University of Wisconsin-Madison suggests that micrometer-sized droplets of liquid crystal, which have been found to change their ordering and optical appearance in response to the presence of very low concentrations of a particular bacterial lipid, might find new uses in a range of biological contexts. Detecting endotoxin, a lipid-polysaccharide combination that is found in the outer membranes of many types of bacteria, is a standard way to establish the presence of bacterial contamination in a wide range of drugs, medical supplies and equipment. The current technology is based on a complex mixture of proteins isolated from the blood of a horseshoe crab, says Nicholas Abbott, a professor and the chair of chemical and biological engineering at UW-Madison.
