Downstream processing aims to isolate and purify the target product from a complex mixture, which may contain impurities, contaminants, and other undesired substances.

Crystallization is not typically used in downstream processing, as it is primarily employed for the purification of solid compounds, whereas downstream processing focuses on the separation and purification of biomolecules.

Cell disruption is employed to break open the cells and release their intracellular contents, which may contain the desired product or other valuable biomolecules.

Size-exclusion chromatography (SEC) is widely used for the separation of proteins based on their size, as it allows molecules of different sizes to elute from the column at different times.

Ion-exchange chromatography separates molecules based on their charge, as positively charged molecules bind to negatively charged resins, while negatively charged molecules bind to positively charged resins.

Size-exclusion chromatography is not commonly used for the purification of antibodies, as it separates molecules based on their size, which is not a primary factor in antibody purification.

Ultrafiltration is used to concentrate the desired product by selectively allowing smaller molecules and impurities to pass through the membrane, while retaining the larger molecules of interest.

Size-exclusion chromatography is not commonly used for the purification of nucleic acids, as it separates molecules based on their size, which is not a primary factor in nucleic acid purification.

Lyophilization (freeze-drying) is primarily used to remove water from the product, which increases its stability and shelf life by preventing microbial growth and chemical degradation.

Reversed-phase chromatography is not commonly used for the purification of enzymes, as it is primarily employed for the separation of small hydrophobic molecules, whereas enzymes are typically large and hydrophilic.

Sterile filtration is employed to remove bacteria and other microorganisms from the product, ensuring its sterility and preventing contamination during storage and use.

Reversed-phase chromatography is not commonly used for the purification of carbohydrates, as it is primarily employed for the separation of small hydrophobic molecules, whereas carbohydrates are typically large and hydrophilic.

Crystallization is employed to obtain the desired product in a solid form, which facilitates its handling, storage, and transportation, and also improves its stability and purity.

Size-exclusion chromatography is not commonly used for the purification of lipids, as it separates molecules based on their size, which is not a primary factor in lipid purification.

Drying is employed to remove water from the product, which increases its stability and shelf life by preventing microbial growth and chemical degradation.