What is the polydispersity index?

Polydispersity Index (PDI) is a parameter that describes the relative distribution of molecular sizes in a sample. Unlike substances with uniform molecular size, some materials, such as aggregates and biopolymers, exhibit a range of lengths and sizes. The PDI quantifies this variability, providing insight into the sample's heterogeneity. Because of its resolution and precision, FIDA can detect subtle size heterogeneity. How to interpret the readout? Values greater than 0.05 indicate polydispersity (meaning the sample contains molecules of varying sizes). In general,  higher PDI values signify a broader distribution of molecular sizes, indicating greater variability within the sample. Understanding PDI is essential in fields like polymer science and biotechnology, where the size distribution of molecules can impact material properties and functionality.

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