Downstream processing is a critical stage in biotechnology and chemical engineering that involves the separation, isolation, and purification of a desired product (such as a protein, enzyme, or other organic compound) from the biological materials (e.g., cell culture, fermentation broth) in which it was produced. This multi-step process ensures the final product meets the necessary purity and quality standards for its intended use, such as in pharmaceuticals, food ingredients, or industrial enzymes. Key techniques used in this phase include filtration, centrifugation, extraction, and various types of chromatography.