In this online presentation, Dr Moritz Susewind from PSS Polymer Standards Service GmbH goes into detail about the applications and challenges in method development and optimisation of SEC analyses. What is needed for SEC is explained in detail. The hardware and software for lightscattering are discussed in detail, as well as the biocompatible columns required. Dr Susewind compares the light scattering detector and the UV detector with examples. The different columns are also clearly compared with each other using graphics.