Fluorescent micrographs with representative images of DNA damage detected in vitrified-warmed mouse blastocysts. Nuclei of blastomeres stained with DAPI showing blue fluorescence. Nuclei with DNA strand breaks were labeled using the TUNEL assay. Damaged cells bound TMR-red dUTP and exhibited red fluorescence. A-C: Blastocysts vitrified on CryoTip and stored in LN2. TUNEL staining was performed 3 hours after warming. D-E: Blastocysts vitrified on CryoTip and stored in vapor phase under transport conditions. Stained 3 hrs post warming. G-Blastocyst vitrified on cryoloop and stored in LN2 (3 hrs post warming). H-Cleavage stage embryo vitrified on cryoloop and stored in LN2. TUNEL labeling 48 hours after warming.