X-Ray Microscopy at Suboptical Resolution: Direct Observation of the 65-nm Periodicity in Collagen Fibrils

Using a Fresnel zone plate we demonstrate for the first time the direct visualization by x-ray microscopy of suboptical regularity in a biological specimen, namely the 65-nm axial periodicity of tendon collagen. This resolution test demonstrates a resolving power of about 20λ; a resolving power of <10λ is in prospect.