This educational session will focus on some of the new demands in counting particles in liquids, with a focus on the challenges of preparing and sampling protein-based materials. USP has recently posted a new test for protein-based materials, known as USP <787>, and indicated that a companion informational chapter, USP <1787>, will be crafted to further describe methods and options for evaluating protein-based materials. This presentation will delineate the differences between the more well-known USP 788 and the new USP 789, focusing on critical sample preparation and handling to provide good data on particulate concentration in protein solutions. Two types of instruments that could be employed for this method are discussed and compared, one based on light obscuration and a second on the Coulter principle.

Learning Objectives:

• Learn about the new demands in counting particles in liquids, with a focus on the challenges of preparing and sampling protein-based materials
• Learn about the new test USP has recently posted for protein-based materials, known as USP <787>
• This presentation will delineate the differences between the more well-known USP 788 and the new USP 789, focusing on critical sample preparation and handling to provide good data on particulate concentration in protein solutions
• Learn about and compare two types of instruments that could be employed for this method, one based on light obscuration and a second on the Coulter principle