The scientific career of one of the most outstanding scientists in molecular thermodynamics, Professor John M. Prausnitz at Berkeley, reflects the change in the agenda of molecular thermodynamics, from hydrocarbon chemistry to biotechnology. To make thermodynamics a frontier for biotechnology will require much dedicated research to demonstrate the needs. Emphasis must be directed towards understanding the processes and the important issues in the development of novel biopharmaceutical products. Following an introduction to indicate the influence it made on oneself and the difference it made, attention will be given to some important thermodynamic issues related to the recovery of biopharmaceuticals, including an outline of the progress in the area of applied thermodynamics of chromatography and its applications at the IVC Research Centre at DTU. (c) 2006 Elsevier B.V. All rights reserved.