How do I harvest the crystals from meso phase? Are special tools needed?

No special tools are needed (normal loops). You can put the crystals directly in the beam. If you have to transport the crystals, the best is to transport them in the plate, but if you have to transport them, a cooling deware filed with Nitrogen it is OK.  To get the best diffraction, it is important to try various cryo protection solution

Membrane proteins of various sizes and configurations have been reported to crystallize in meso phase.