Section 10.1.2.3. Removal of the solvent layer

Because of their tendency for rapid loss of internal solvent, dried biocrystals rarely survive exposure to the atmosphere. A solution to this problem was described by Hope (1988). The solvent is removed while the crystal is submerged in a hydrocarbon oil. After the liquid has been removed, a small drop of oil is allowed to encapsulate the crystal, allowing it to tolerate brief exposure to air. Even under such mild conditions, some crystals still lose water and suffer damage. A remedy for this is to keep the oil saturated with water. One disadvantage of the oil technique is the tendency to carry along too much oil, which can cause excessive background scattering. One advantage is that absorption can become nearly isotropic. The most commonly used oil is Infineum Parabar 10312, formerly known as Exxon Paratone-8277 or Paratone-N.