Interferometric Studies on the Concentration Variations around a Growing Protein Crystal

The concentration fluxes in the vicinity of protein crystals growing from its aqueous solution has been investigated using laser based interferometric technique. A Mach-Zehnder interferometer has employed for the experimentation. Lysozyme (Hen-Egg-White) has used as the protein, where sodium chloride (Nacl) is used as the precipitant and Sodium acetate (CH3COONa) as buffer. A test cell with dimensions 22.5 mm of height and 24 mm of width made up of high quality optical glass has used as the test chamber, so as to make optical measurements feasible. The Lysozyme crystals have inserted into the supersaturated solution inside the test chamber to initiate the growth process. Wedge fringe interferograms has been employed to retrieve the concentration gradients around the crystal during the growth/dissolution process. The results from the experiments are summarized in the form of interferograms during the growth/dissolution process, two dimensional concentration gradients around the crystal etc.,