Black and Veatch 1 article published in JoVE Environment Quantifying Elastic Properties of Environmental Biofilms using Optical Coherence Elastography Evan Dieppa1, Hannah Schmitz2, Ziwei Wang3, Fabrizio Sabba4, George Wells2, Oluwaseyi Balogun1,2,3 1Theoretical and Applied Mechanics Program, Northwestern University, 2Civil and Environmental Engineering Department, Northwestern University, 3Mechanical Engineering Department, Northwestern University, 4Black & Veatch This paper highlights the optical coherence elastography (OCE) technique's efficacy in rapidly and non-destructively characterizing biofilm elastic properties. We elucidate critical OCE implementation procedures for accurate measurements and present Young's modulus values for two granular biofilms.