Professor, Department of Chemical and Biological Engineering
Rensselaer Polytechnic Institute

Education:
Ph.D., Chemical Engineering, Yale University, 1986
M.S., Chemical Engineering, Yale University, 1982
B.S., Biomedical Engineering, Brown University, 1978

Career Highlights:
Cramer joined the Rensselaer Chemical Engineering faculty in 1986 and was named the Isermann Associate Professor of Chemical Engineering at Rensselaer in 1990; he was promoted to full professor in 1995. Prior to his university roles, Cramer worked for three years as a research engineer at Amicon Corporation in Lexington, Massachusetts.

A Fellow of the American Institute for Medical and Biological Engineering, Cramer also has won a Presidential Young Investigator Award from the National Science Foundation, the Early Career Award from Rensselaer, and several teaching awards.

Cramer is an active professional contributor to his field; he was a co-chair for the Recovery of Biological Products meeting in Cancun, Mexico in 2001 and chair of the 1999 Gordon Conference on Reactive Polymers and Ion Exchange. He has been the executive editor of the journal Separation Science and Technology since 1996, has served on the editorial boards of Isolation and Purification and Separation and Purification Methods, and was a special associate editor of Biotechnology and Bioengineering. Cramer is a frequent consultant with several biotechnology and separations companies in the United States and Europe. During his career, he has published over 110 professional articles and holds several key patents in the bioseparations field; his lab has also produced over 20 doctoral students who have gone on to leadership roles in the biotechnology industry and academia.

Research Areas:
Cramer has become a recognized expert in the fields of chromatographic bioprocessing and separation science. The research conducted in his laboratory involves novel bioseparation techniques for simultaneous concentration and purification of biomolecules. These studies involve a detailed analysis of the thermodynamics and transport involved in these processes, as well as a fundamental investigation into the nature of affinity in these non-linear chromatographic systems.

His major focus to date has been on displacement chromatography, a technique that takes advantage of the non-linearity and competitive nature of the adsorption of biomolecules at high concentrations. This work resulted in the discovery that low molecular weight compounds with appropriate chromatographic properties can be employed as efficient displacers for protein purification. Cramer’s group has developed powerful new models of non-linear ion exchange and immobilized metal affinity chromatographic systems. In addition, they have applied their theoretical and experimental expertise in non-linear chromatography to the optimization of gradient chromatographic systems.

Team members recently expanded their research to include non-linear hydrophobic chromatographic systems, high throughput screening, computational chemistry, Raman spectroscopy, and chip technology.

Selected Publications:
A. Ladiwala, K. Rege, C. Breneman, and S.M. Cramer, “Mobile Phase Salt Type Effects on Protein Retention and Selectivity in Cation Exchange Systems,” Langmuir, 19, (20), 8443-8454, (2003).

N. Tugcu, A. Ladiwala, C. Breneman, and S.M. Cramer, “Identification of Chemically Selective Displacers Using Parallel Batch Screening Experiments and Quantitative Structure Efficacy Relationship Models,” Analytical Chemistry, 75, (21), 5806-5816, (2003).

N. Tugcu, M. Song, C. Breneman, and S.M. Cramer, “Prediction of the Effect of Mobile Phase Salt Type on Protein Retention and Selectivity in Anion Exchange Systems,” Analytical Chemistry, 75, (14), 3563-3572, (2003).

K. Rege, N. Tugcu, and S.M. Cramer, “Predicting Column Performance in Displacement Chromatography from Batch Screening Experiments,” Separation Science and Technology, 38, (7), 1499-1517, (2003).

K. Sunasara, F. Xia, R.S. Gronke, and S.M. Cramer, “Application of Hydrophobic Interaction Displacement Chromatography for an Industrial Protein Purification,” Biotechnology & Bioengineering, 82, (3), 330-339, (2003).

F. Xia, D. Nagrath, and S.M. Cramer, “Modeling of Adsorption in Hydrophobic Interaction Chromatography Systems Using a Preferential Interaction Quadratic Isotherm,” Journal of Chromatography, 989, (1), 47-54, (2003).

N. Tugcu, R.R. Deshmukh, and Y.S. Sanghvi, et al., “Displacement Chromatography of Anti-Sense Oligonucleotide and Proteins Using Saccharin as a Non-Toxic Displacer,” Reactive and Functional Polymers, 54, (1-3), 37-47, (2003).

D. Nagrath, B.W. Bequette, and S.M. Cramer, “Evolutionary Operation and Control of Chromatographic Processes,” AIChE (American Institute of Chemical Engineers journal), 49, (1), 82-95, (2003).

N. Tugcu, S.K. Park, J.A. Moore, and S.M. Cramer, “Synthesis and Characterization of High-Affinity, Low-Molecular-Mass Displacers for Anion-Exchange Chromatography,” Industrial & Engineering Chemistry Research, 41, (25), 6482-6492, (2002).

M.H. Song, C.M. Breneman, J.B. Bi, N. Sukumar, K.P. Bennett, S.M. Cramer, and N. Tugcu, “Prediction of Protein Retention Times in Anion-Exchange Chromatography Systems Using Support Vector Regression,” Journal of Chemical Information and Computer Sciences, 42, (6), 1347-1357, (2002).

V. Natarajan, S. Ghose, and S.M. Cramer, “Comparison of Linear Gradient and Displacement Separations in Ion-Exchange Systems,” Biotechnology & Bioengineering, 78, (4), 365-375, (2002).

Contact Information:
Steven Cramer
(518) 276-6198
crames@rpi.edu
http://www.rpi.edu/~crames