Painting with crystals

Preparing a normal or time lapse video of a crystallization process under the microscope is not easy. Focusing problems, formation of too big crystals and getting the interesting part right under the objective, often gives you a headache.

With the technique described below, most of these headaches can be overcome:

• Prepare a saturated solution of some chemical in water or another solvent.
• Use a slide with some print on it (e.g. the manufacturers name) in order to set focus already before crystallization starts.
• Apply an ultra-thin (‘nano’) layer of clear liquid soap (or another surfactant) on the slide, by wiping it almost off with your finger.
• Bring a droplet of saturated solution on the slide. It will spread evenly in a very thin layer over a relative big surface, because of the surfactant applied.
• Do not put a cover glass on top of it, it will disturb crystallization. This is also not needed for 2X, 4X or 10X objectives.
• Put the slide under the microscope and use the manufacturer’s print to focus.
• Just wait, crystallization will start after a relative short while and it will proceed fast because of the thin liquid layer.
• The result will be a thin layer of crystals suitable to bring it almost entirely into depth focus.
• Then take still images using polarized light and a lambda filter if desired, in order to pre-adjust the camera for color, sharpness etc.
• Now the real work starts: prepare the sample as explained above and keep the camera stand by. Not necessarily for time lapse but for video because crystallization will start soon and will take place over a period of minutes.
• When crystallization is proceeding, search in the sample for nice effects.
• Cut and paste the best scenes with a video editing program like it was done in the ‘Painting with crystals’ video.

©Willem Cramer