Methods to assay fibrillar growth and degradation at sub-light scales include: fluorescence assays using FITC-collagen or FRAP, destructive preparation and measurement using electron microscopy, and light occlusion methods including turbidity and absorption methods. Many of these methods require the outright destruction, or at least modification via labelling, of the sample in question. This requirement can slow experimentation and introduce additional variability or even alter the reaction rate kinetics. The two methods (absorption and turbidity) which are label-free are bulk averaging methods and cannot isolate subsets of fibrils (e.g. fibrils under load).
IEEE Press Series on Electromagnetic Wave Theory
