Bar codes have revolutionized how everyone from warehouse managers to pharmacists keeps track of items. Mountain View, CA-based SurroMed is using them to help biologists track genes, proteins and other molecules. SurroMed's microscopic bar codes could eventually be used to identify and quantify thousands of different molecules in a sample of a fluid like blood, making biological and medical tests far more informative.

Select from the choices above to read the entire article.