- This is the microscope image format. See Mixed Raster Content for the graphic compression format, and MIRC scripting language for the scripting language which sometimes uses a .mrc extension.
MRC is a format for representing microscope images used in processing microbiological or chemical data, storing its data in "voxels".
The varieties of this format are used for 3D imaging in electromicroscopy, storing a map of electron density. There is an obsolete pre-2000 MRC format, a newer MRC 2000 format, and some format variations on the older format. Files start with a 1024-byte header organized into 56 words followed by 10 80-byte text labels.