Computational Challenges for 3D Atomic Structure Determination of Large Macromolecules using Cryo-TEM. Dan C. Marinescu Computer Sciences Department Purdue University West Lafayette, IN 47907 Email: dcm@cs.purdue.edu Abstract Real-time CryoTEM requires algorithms for automatic particle identification and parallel algorithms for orientation determination and 3D reconstruction. The talk will review our results and discuss the current status of an infrastructure for a virtual laboratory for computational biolgy. Dan C. Marinescu is Professor of Computer Sciences at Purdue University He is conducting research in parallel and distributed computing, and software agents. He was the chief architect of a distributed data acquisition and analysis system used in nuclear physics, now he is the PI of an NSF funded Grand Challenge project to solve large structural biology problems using parallel and distributed systems and the Director of the Bond project (http://bond.cs.purdue.edu).