Common conventions for interchange and archiving of three-dimensional electron microscopy information in structural biology

Three-dimensional electron microscopy (3DEM) has made significant contributions to structural biology. To accomplish this feat, many image-processing software packages were developed by various laboratories. The independent development of methods naturally implied the adoption of dissimilar conventions—penalizing users who want to take advantage of the wealth of algorithms from different packages. In addition, a public repository of 3DEM research results, the EM Data Bank, is now established. In an era where information exchange is important, standardizing conventions is a necessity. The 3DEM field requires a consistent set of conventions. We propose a set of common conventions named the “3DEM Image Conventions.” They are designed as a standardized approach to image interpretation and presentation. In this regard, the conventions serve as a first step on which to build data-exchange solutions among existing software packages and as a vehicle for homogenous data representation in data archives, such as the EM Data Bank.