Automatic Particle Picking Algorithms for High Resolution Single Particle Analysis

As new genome sequencing initiatives are completed, one of the next great challenges of cell biology is the atomic resolution structure determination of the enormous number of proteins they encode. Single particle analysis is a technique which produces 3D structures by computationally aligning high resolution electron microscope images of individual, randomly oriented molecules. One of the limiting factors in producing a high resolution 3D reconstruction is obtaining a large enough representative dataset ( 100,000 particles). Traditionally particles have been picked manually but this is a slow and labour intensive process. This paper describes two automatic particle picking algorithms, based on correlation and edge detection, which have been shown to be capable of quickly selecting a large number of particles in micrographs. Currently circular and rectangular particles are able to be picked.