Capillary-Tube Chemotaxis Assay (IMAGE) University of Hawaii at Manoa Caption A tiny glass tube containing a concentrated solution of a chemoattractant (that is, a fatty acid) is placed into a suspension of motile Vibrio fischeri cells. Within a few minutes the bacteria have swum to the tip of the tube, where the concentration of the attractant is highest. The bright area is the cloud of bacteria accumulating around the tip. Credit E. Ruby, University of Hawaii / PBRC. Usage Restrictions Image may be used with appropriate caption and credit. 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.