The Year in Review from Process Development Forum What you watched, read and reviewed in 2012 How to elute proteins from multi-modal chromatography resins (tip). Mixed mode ion exchangers frequently exhibit useful selectivity that can be exploited to achieve purification in fewer steps. Frequently, both a pH change and an increase in salt concentration are required for effective elution of bound proteins. The general recommendation is to screen for both pH and conductivity. Also, one should include loading conditions in the screening, as this may affect the elution efficiency. Finally, one could consider different salts and the use of additives. Design-of-Experiments (DoE) is recommended to characterize conditions. Read the tip. Design of Experiments Video. Mattias Ahnfelt, (SIX Sigma Master Black Belt in the Biotechnology business of GE Healthcare Life Sciences), explains how DoE systematically covers the investigated process space, resulting in reliable quantification of cause and effect, as well as random process variation. Watch the video New Tech Report for Bio Cleaning Validation: Quality by Design principles such as design space can also be applied to cleaning validation. As discussed in the recently published PDA Technical Report No. 49: Points to Consider for Biotechnology Cleaning Validation, well–designed laboratory-scale studies can be performed using design of experiments, and the data analyzed to understand the cleaning process. With the knowledge of large-scale equipment, one can create an approach that results in a successful cleaning validation. Review the Report Challenges for Biosimilar Developers—A Conversation with Dr. Howard Levine. On February 9, 2012, almost two years after the Biologics Price Competition and Innovation Act was passed, FDA released draft guidelines concerning the regulatory path for biosimilars. Amy Ritter, Scientific Editor at BioPharm International, spoke with Dr. Howard Levine, President and Principal Consultant of BioProcess Technology Consultants, about what these guidelines mean for developers of biosimilars. Review the interview Optimizing Process Control in WAVE Bioreactors (poster). Disposable bioreactor technologies have been mainstream for over a decade, and like the traditional stainless-steel bioreactors, rapid progress has been achieved in the area of process control. This progress has been accelerated by the emerge of single-use or non-invasive probe technologies. Review the poster Question: Like what you read? Want to see more of something in particular? Let us know what topics are on your mind and what you'd like to see more of in 2013.