  Motion of protein drops on crystallization media during routine handling is a
major factor affecting the reproducibility of crystallization conditions. Drop
stability can be enhanced by chemical patterning to more effectively pin the
drop's contact line. As an example, a hydrophilic area is patterned on an
initially flat hydrophobic glass slide. The drop remains confined to the
hydrophilic area, and the maximum drop size that remains stable when the slide
is rotated to the vertical position increases. This simple method is readily
scalable and has the potential to significantly improve outcomes in hanging and
sitting drop crystallization.
