Grids are considered “Krios-ready” if the same grids have been screened in another auto-loader system or identical replicas of the grids were screened via side-entry microscopes.
Grids are considered pre-screened when the freezing parameters have been assessed under cryo conditions and confirmed as high-quality samples. Each batch of grids that has been frozen should be assessed for optimal ice quality, sample concentration, and particle distribution. Pre-screening ensures high-quality grids for data collection.
Grids that are not pre-screened generally will not have successful data collection results. If you are screening grids at your local facility, please make sure to take enough images to fill out our Pre-Screened Grid Form when requesting to Schedule Experiments. PNCC created a guide to help determine “Krios-ready” grids here.