Paracrystals of the isolated Tn-Tm complex were grown on a positively charged lipid monolayer and negatively stained. Single particles were selected from digitized electron micrographs ensuring that particles were clearly separated from neighbouring molecules. Two-dimensional alignment, multivariate statistical analysis and classification lead to five stable averages that were then used to reconstruct a three-dimensional model applying the common line approach. Refinement of the model was performed by weighted back projection on a data set of 1142 selected particles.