Protein Crystal Harvesting Using the RodBot - a Wireless Mobile Microrobot

We have developed a novel device for the automatic or semi-automatic harvesting of delicate macromolecular crystals out of standard crystallographic hardware.
The idea behind our technique is that instead of an extraction device chasing after a crystal, the crystal is brought to a conveniently positioned loop in the droplet. This is achieved by a magnetically driven micro-agent, the RodBot. The RodBot can be guided to a particular position in the droplet to select a desired crystal and then transport it to and place it onto the loop using gentle fluid flows as the motive force. The loop doesn't need the dexterity of a human hand to be able to access all regions of a droplet and then get hold of the crystal, and can thus be held by a simple, inexpensive mechanical linkage. There are no problems with the unsteadiness of an operator's hand, which often leads to the accidental destruction of delicate crystals, or the loss of the crystal while it is being extracted from the droplet. Our technique provides a reliable system that is inexpensive to operate and that works with standard crystallization hardware. It is suitable for both home-lab use and for incorporation into more complex, fully automated platforms.