Through the use of lasers, the detection and monitoring of E. coli microbes is become a simple automated method.  Microbial contamination of water is the leading causes of illness and death in the world.  This is even a problem in civilized society as well.  Great evidence is the increasing use of boil water advisories beaucse of waterborme disease outbreaks.  Bin Chen of Purdue Universitry, and help from others, use the high-resolution optical scattering image analysis to identify E. coli in lab samples.  More research needs to go into making this technique commerically viable.  

The website is below if this technqiue or article interested you, don't be scared!!

http://www.waterworld.com/index/display/article-display/6620473260/articles/waterworld/environmental0/water-quality/2011/01/Speeding-up-E-coli-detection-with-lasers.html