In this experiment, Thaumatin crystals are produced by mixing a 70 mg./mL buffered solution of Thaumatin protein with a Sodium Potassium Tartrate salt solution.  The salt solution has a higher affinity for water than the protein solution. So, mixing the two results in an increasing concentration of the Thaumatin solution as the salt draws the water away from the protein. When the concentration of the protein solution reaches the correct point, crystallization occurs.  The rate of crystallization can be controlled by trying various concentrations of salt solutions. Higher concentrations of salt solutions should result in faster crystallization and smaller less perfect crystals.  Lower concentrations of salt should result in slower crystallization and potentially larger and more perfect crystals.

An additional factor controlling the rate of crystallization in the set up of this experiment procedure is the selection of a capillary tube as the vessel for the crystallization.  Capillary tubes decrease the rate of diffusion which results in a slower rate of crystallization than would be experienced in a less restrictive vessel (i.e. a drop) for all salt concentrations.

First Step Procedures

The first step in the Thaumatin crystallization process in this experiment was to select which concentration (molarity) of the Sodium Potassium Tartrate salt solution would result in the optimum rate of crystallization, crystal size and clarity.  The most desirable rate of crystallization would be a relatively long duration so that the crystals would be subject to the effects of the magnetic field for a long period of time. But, the period of crystallization had to be short enough that the crystals could be observed and results recorded in a practical amount of time.

The first step trial consisted of making three capillary tube samples of each salt concentration (.4 M, .5M, and .6M) in separate petri dishes.  This was initiated on February 1, 2002

First Step Results

The following Thaumatin images were produced by Anna Holmes from
Protein Crystals grown in the initial .5M solution

Meeting with Anna Holmes on Monday, February 11th