Indigoidine Dish (IMAGE) Utah State University Caption USU researchers have patented a new method to produce the deep blue dye known as indigoidine using E. coli as a heterologous host. Credit USU Engineering Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.