Downstream processing and analytical bioseparation both refer to the separation or purification of biological products, but at different scales of operation and for different purposes.
A widely recognized heuristic for categorizing downstream processing operations divides them into four groups which are applied in order to bring a product from its natural state as a component of a tissue, cell or fermentation broth through progressive improvements in purity and concentration.
Typical operations to achieve this are filtration, centrifugation, sedimentation, precipitation, flocculation, electro-precipitation, and gravity settling.
Additional operations such as grinding, homogenization, or leaching, required to recover products from solid sources such as plant and animal tissues, are usually included in this group.
For example, expanded bed adsorption (Vennapusa et al. 2008) accomplishes removal of insolubles and product isolation in a single step.