What are the common variables that decrease molecule passage?

Common Variables That Decrease Molecule Passage:

• Buffer conditions that facilitate aggregation of molecules 
• High sample concentration exceeding 10 mg/mL 
• Presence of other molecules that increase sample concentration 
• Low temperatures 
• Molecule adsorption to the membrane or device 
• Reduced transmembrane pressure such as lower gravitational force in case of centrifugal concentrators