A MICROFLUIDIC METHOD FOR OPTICAL STUDIES OF EARLY STAGE BIOFILM RESPONSE TO APPLIED SHEAR STRESSES

摘要

Shear stresses are applied against growing biofilms in microchannels by a flowing nutrient solution. At certain times, the biofilms respond by moving in the direction of the flow. The displacement velocity of visibly identifiable biofilm segments and their changing optical density was monitored with optical microscopy and quantitatively analyzed by a semi-automated particle tracking routine. The method is used to reveal subtle differences in the response of cultivated biofilms based on their growth times and location in the channel. Following the demonstration of the approach, we discuss the potential of a system that employs highly-paralyzed microchannels and automated data acquisition for high-throughput measurements of biofilm displacement in different hydrodynamic and chemical environments.