Prototype selection (PS) is a suitable data reduction process for refining the training set of a data mining algorithm. Performing PS processes over existing datasets can sometimes be an inefficient task, especially as the size of the problem increases. However, in recent years some techniques have been developed to avoid the drawbacks that appeared due to the lack of scalability of the classical PS approaches. One of these techniques is known as stratification. In this study, we test the combination of stratification with a previously published steady-state memetic algorithm for PS in various problems, ranging from 50,000 to more than 1 million instances. We perform a comparison with some well-known PS methods, and make a deep study of the effects of stratification in the behavior of the selected method, focused on its time complexity, accuracy and convergence capabilities. Furthermore, the trade-off between accuracy and efficiency of the proposed combination is analyzed, concluding that it is a very suitable option to perform PS tasks when the size of the problem exceeds the capabilities of the classical PS methods.