How Alternating Flow Directions Boost Large Biotherapeutic Purification

Purifying large biotherapeutic entities like viral coat proteins and mRNA is tougher than handling smaller products. These huge molecules struggle to reach binding sites in regular chromatographic media. However, size exclusion chromatography (SEC) offers a potential solution by isolating them in the void fraction of an appropriate SEC column. The challenge lies in improving SEC's low capacity, productivity, and scalability. Enter the alternating flow-direction technique!This method involves feeding the substance from opposite directions alternately, which can significantly shrink the separation time. A prototype cuboid SEC device with Sephacryl S 200 resin was used to test this method. The study focused on purifying the SARS-CoV-2 delta spike protein from smaller impurities in cell-free supernatant. The results? A whopping 42% reduction in time (or mobile phase volume) compared to traditional unidirectional SEC.