Deterministic Loading of a Single Atom to a Micro-Trap Direct observation of single atoms undergoing individual microscopic events has recently become possible. These direct observations are of basic interest, because much of our knowledge of microscopic events today is inferred from macroscopic measurements. On the other hand, these techniques are also of interest to applied research, because they may allow manipulation of matter at the single atom level, with application ranging from metrology to quantum information processing. In this talk, I will describe our new experimental setup and main results. We can trap and count the number of atoms in small and dense atomic samples loaded to an optical micro-trap, and image the trapped atoms with sub- micron resolution. Using this setup, we prepare pairs of trapped atoms and study two-body light assisted collisions, by direct observations. We demonstrate an efficient method of loading a single atom to our micro-trap by tailoring the light-assisted collision parameters.