Biofouling of membranes used in high-pressure applications has been and will continue to be a problem that must be addressed in industry as well as academia. Many of these applications use membranes in a spiral wound configuration that contains a feed spacer. When anti-biofouling properties were imparted to these feed spacers, through copper chelation, slower rates of biofouling were observed. This study investigated the effects of this modification on flux decline during filtration of a synthetic feed water that contained a high concentration of Pseudomonas fluorescens. Furthermore, some traditional and one novel techniques were implemented to autopsy the membranes after filtration. The novel technique was the use of Fourier Transform Infrared (FTIR) to quantitatively compare the concentration of biofilm components on membranes fouled using both virgin and copper-modified feed spacers.