The cryo-prepared acetate buffer was illuminated at 638 nm excitation wavelength for 1 min at different laser intensities calculated using the FW90M area square shape of 60 by 60 µm. The occurrence of devitrification, i.e., the presence of cubic or hexagonal ice crystals, was examined in cryo-TEM to verify the maximum allowable laser intensity. In addition, cryo-bright field microscopy with the internal LED lamp of the LINKAM cryo-stage was used to assess the damage after laser illumination.