This eBook provides details and insight into using Slope Spectroscopy and the CTech™ SoloVPE® variable pathlength spectroscopy system. The SoloVPE® system provides a rapid, robust, and repeatable, non-disruptive concentration measurement method for proteins, plasmid DNA, and nucleic acid modalities. Articles in this eBook cover a variety of topics including viral filtration integrity, polysorbate UV-Vis spectral and slope analysis, how to measure Co-Oximetry parameters in bovine hemoglobin, accurately calculating the plasmid DNA purity ratio in human gene therapy products, techniques for real-time biomanufacturing process monitoring, and the application of in-line variable pathlength chromatography for high-concentration oligonucleotide solutions.