Bovine serum albumin (BSA) is a globular protein that’s extracted from cow blood. It is the most common standard used in protein concentration quantitation assays to analyze the concentration of protein in a solution. BSA offers several advantages that make it the preferred standard for protein assays: 

• Has the ability to boost signal in assays 
• Does not react with other enzymes in biochemical reactions 
• Has higher sensitivity
• Is stable at room temperature for up to 3 weeks
• Gives consistent results
• Compatible with common substances in samples
• Is small and can be easily stored
• Easily mass-produced and readily available 
• Affordable