Cellulose is a commercially important biopolymer. Due to its abundance, biocompatibility and renewability it has shown important commercial applications in food, pharmaceuticals, biomedical. Depending on the origin and the processing methods used, the resulting fiber dimensions, structure, crystallinity and molecular weight (MW) can vary over a broad range. MW is one of the most important parameters in polymer characterization as many of its properties depend on it. Gel permeation chromatography (GPC) has been the technique of choice for determining these properties.