The present work is based on the previously reported purification study of TaqI endonuclease(5) and aimed to simulate the experimentally obtained chromatograms in order to reduce the time and cost in the design, optimization and scaling up of purification processes. Three different models depending on equilibrium, rate and plate theories are used in the mathematical description of experimental elution profiles and the solutions of the model equations are compared. The equilibrium-dispersive theory provides excellent results in predicting the experimental chromatograms. It is thus recognized that band dispersion takes place in the column through axial dispersion and nonequilibrium effects. The user-friendly software written in Visual Basic can be used in the design of purification processes as well as in the determination of optimal separation conditions for many other enzymes.