journal menu
![[Figure 11]](kk5077fig11mag.jpg)
|
|
Figure 11
A simple-to-construct low-cost vapor-diffusion crystallization experiment using a plastic Petri dish. A disposable polystyrene Petri dish is easily adapted for setting up a hanging-drop vapor-diffusion crystallization experiment. The lid of the plate is removed and Vaseline applied around the inside rim using a syringe, or simply painting it on with a cotton swab. Once the grease seal is applied to the perimeter, the protein and crystallization cocktail drops are sequentially added to the inside of the lid (the same side as the grease seal). It is important to mark the lid so that drops can be identified later. Recommended volumes are 5 µl each of protein and cocktail, and 1.0 µl of any additive. Any of the illustrated devices (e.g. adjustable pipette, Hamilton syringe, Wiretrol) can be used to dispense the drops. The volumes of these components, the volume ratios, the order of adding the components, and mixing or leaving the drops undisturbed after delivery are all variables the students can pursue if a more comprehensive investigation is undertaken. A volume of reservoir solution is added to the bottom of the Petri dish (10 ml), and the lid is inverted over the bottom of the plate and pressed to ensure the Vaseline will form a good seal. |
![[Figure 11]](kk5077fig11.jpg)
 | JOURNAL OF APPLIED CRYSTALLOGRAPHY |
ISSN: 1600-5767
