(color online) 3D reconstruction of DNA-nanogold conjugates by IPET. (a) Images using ET of DNA-nanogold conjugates from a series of tilt angles. (b and (f) Tilt images of DNA-nanogold conjugates, then after CTF correction aligned to a common center for 3D reconstruction via an iterative refinement process and final 3D reconstructions at the corresponding tilt angles. (c) and (g) Final IPET 3D density maps of the targeted individual particles are obtained. (d) and (h) The final 3D density map indicated the overall conformation of the DNA-nanogold conjugates. (e) and (i) FSC analyses show that the resolution of these 3D maps are ∼14 Å. Adapted from Ref. [59].