Peptides (IMAGE) DOE/Pacific Northwest National Laboratory Caption The peptides in this highly ordered two-dimensional array avoid the expected nucleation barrier by assembling in a row-by-row fashion. Credit PNNL Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.