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Principles of Gel Permeation Chromatography presents the principles of gel permeation chromatography (GPC) for students in introductory undergraduate courses of chemistry and biochemistry. These principles are presented in four sections: Introduction, Real Lab, Virtual Lab, and Microscopic Model (Figure 1).
The Introduction and Real Lab sections present a brief view of the basic experimental apparatus typically used in laboratory GPC in order to provide a concrete connection of the real process of separation (1). The basic elements of column chromatography, emphasizing the stationary and mobile phases, are presented in the Introduction, followed by a sequence of pictures and texts describing major steps in GPC analysis in the Real Lab section.
The Virtual Lab section is a simulator (2, 3). Three samples are available for a virtual GPC experiment: sample 1, containing hemoglobin; sample 2, containing methylene blue; and sample 3, containing both methylene blue and hemoglobin. Each sample undergoes a virtual separation run, which is dynamically represented in three ways in the software: a virtual column, the collected fractions, and a virtual chromatogram. This threefold representation allows the simultaneous view of key aspects of the process to demonstrate the correlation between the experimental procedure and the resulting chromatogram (4, 5).
Figure 1. The three elements of the Virtual Lab section of Principles of Gel Permeation Chromatography: Interactive Software.
The Microscopic Model section is an animation representing the microscopic separation phenomenon in GPC. The animation can be paused and resumed anytime, allowing the examination of the molecular motions within the gel matrix.
For pedagogical reasons, all the processes represented in the software have been simplified in order to facilitate students’ comprehension of the key elements of the separation phenomenon (6, 7).
The software is designed so that students move logically from the Introduction through to the Microscopic Model in a way that parallels macroscopic to microscopic, experimental to model, and concrete to abstract pedagogical approaches. However, students are still free to move about within the sections of the software in any order so that different educational strategies can be addressed, and so that exploration is encouraged.
The class activity included on the Web site has been used in conjunction with the software: Students are arranged in groups of 2–3 people, one computer per group, with the assignment to explore the software using a questionnaire as their guide. The activity is allotted one hour of time, with most of the groups finishing the exercise in about 45 minutes. The software has also been successfully used as a teaching aid in lectures.
Acknowledgments
We are thankful to Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) for supporting the project “Experimental Methods in Biochemistry: Interactive Software”, and to the Department of Biochemistry, University of São Paulo, for its academic support.
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