Protein Crystallization: Hanging Drop
Protein crystallization is influenced by a number of variables. Initially, one must decide what type of setup will be used when attempting to grow a protein crystal.
A common method is hanging drop, which utilizes a process called vapor diffusion. The benefit of vapor diffusion is that it allows for the increase of protein and precipitant concentrations. The concentration is increased due to vapor leaving hanging drop to reach equilibrium with its surroundings.
Hanging Drop Setup:
Note: This setup does not allow for evaporation to take place although it may be used to encourage crystal growth. The cover slip is often sealed in place using vacuum grease.
The contents of the hanging drop includes your protein with its buffer, well solution and sometimes water. A common setup is to use 2 µl of protein solution + 2 µl of well solution, suspended over 998 µl of well solution (the 2 µl are added from the well solution to the hanging drop).
Morten G
January 12th, 2010 at 4:18 AM #
You can also get screw cap hanging drop plates or seal with oil.