Order = structure?

Context:

With traditional microscopy, researchers are only able to image tissues up to depths on the order of 300 microns, or about three times the thickness of a human hair. In that process, tissue samples are cut into thin slices, stained with dyes to highlight different structures and cell types, individually imaged, then stacked back together to create 3D models. The Yale team, by contrast, was able to avoid slicing or staining the organs by relying on natural fluorescence generated from the tissue itself.


http://www.sciencedaily.com/releases/2010/06/100624131439.htm