High-Throughput Crystallization of l‑Alanine Using iCrystal Plates and Metal-Assisted and Microwave-Accelerated Evaporative Crystallization

We present a comprehensive study of high-throughput crystallization of l-alanine (a model amino acid) using circular crystallization platforms (are hereafter referred to as the iCrystal plates) designed to work with the metal-assisted and microwave-accelerated evaporative crystallization (MA-MAEC) technique. The iCrystal plates are constructed using a circular 21-, 95-, and 204-well design that afford for homogeneous microwave heating of all samples. In addition, the iCrystal plates were modified with metal thin films (gold, copper, silver, and nickel), which act as selective nucleation sites for selective crystallization to occur on the surface of the crystallization platforms. Silver thin films were found to be ideal for MA-MAEC applications as compared to other metal surfaces based on the observations of crystal number and size. The size and number of wells on the iCrystal plates were found to have negligible effect on the growth of l-alanine crystals, where all three iCrystal plates were found to have similar crystallization times and yield identical crystal quality. These results imply that one can employ the iCrystal plates for the crystallization of a small number of samples (with 21-well capacity) and a large number of samples (95- and 204-well capacity) with identical yields using the MA-MAEC technique.