Use the Formulation filter to find carrier-free proteins
When purchasing some proteins from vendors, they may include a protein like BSA to improve stability. However, carrier proteins may interfere with some experiments and applications (e.g. positive control on a Western Blot), so you can filter for products that vendors labelCarrier Free in the Formulation filter. To expand your results, you can also consider evaluating products and formulations that are BSA-free too, depending on your experiment needs.