Drops: 0. Drop is empty

0. Drop is empty

Check the entire depth of focus in the drop, try dark field illumination to check for gelatinous precipitate.

If the protein in the drop in the initial screen does not precipitate,

• repeat this condition with a higher protein concentration.
  
• If limited amount of protein is available, place the clear drops over a reservoir with a higher precipitant concentration.

In an optimization step, clear drops can be used for seeding with crystals from neighboring drops.