Dr. Leonard Rome’s lab is using molecular engineering of a naturally occurring cellular structure called a vault to develop a flexible, targetable nano-scale capsule. Vaults are abundant cellular particles of unknown function found in nearly all eukaryotes (cells containing a nucleus). Cryo-electron microscopy combined with single particle reconstruction has provided overall dimensions of the vault at 42 x 75 nanometers (a nanometer is a millionth of a meter). These measurements indicate that the vault is larger in mass and size than many viruses. The overall structure of the intact vault is like a hollow barrel with two protruding caps and an indented waist with a very thin shell surrounding an internal cavity large enough to encompass several hundred proteins. Thus, the vault particle is a nanocapsule with incredible potential for compound encapsulation, protection, and delivery. Using a well-characterized insect virus into which a cloned gene can be easily inserted, it is possible to produce large quantities of a given protein in cultured insect cells.