X-tal protocols

Drops: 5. Phase seperation.

Protein Detergent Methods Euipment Screen Drops Reference

5. Phase seperation.

Temperature has an important influence on the equilibrium, so be careful not to heat the drop during examination. Sometimes crystals grow in the highly concentrated protein phase. Because of the unknown composition of the protein phase surrounding the crystal, mounting crystals can be a problem. Try freezing the crystal directly from the drop.

phase seperation Protein or detergent as a film on the outside of the drop. This can be seen best at the interface of the drop and cover slip. Often seen when using PEG or high salt/detergent.
phase seperation

phase seperation
The protein is visible as small droplets within the drop. If the shape of the droplets is irregular it could be Spherulites. Check the drop with polarised light.

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