The JASCO BeStSel CFR Program is an advanced application software designed for accurate secondary structure estimation of proteins through Circular Dichroism (CD) spectroscopy. It offers robust control and analysis for JASCO CD spectrometers, leveraging the BeStSel algorithm to enhance precision by considering β-strand orientation and the twist of antiparallel β-sheets. With GxP compliance and batch processing capabilities, it facilitates objective evaluation and comprehensive biomolecular structural analysis.